Common Weakness Enumeration

CWE-1321

Allowed

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Abstraction: Variant · Status: Incomplete

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

863 vulnerabilities reference this CWE, most recent first.

GHSA-6XWR-Q98W-RVG7

Vulnerability from github – Published: 2022-04-13 00:00 – Updated: 2022-04-22 20:32

Summary

Prototype Pollution in nconf

Details

nconf before 0.11.4. When using the memory engine, it is possible to store a nested JSON representation of the configuration. The .set() function, that is responsible for setting the configuration properties, is vulnerable to Prototype Pollution. By providing a crafted property, it is possible to modify the properties on the Object.prototype.

Severity

7.3 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "nconf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.11.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-21803"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-04-22T20:31:22Z",
    "nvd_published_at": "2022-04-12T16:15:00Z",
    "severity": "HIGH"
  },
  "details": "nconf before 0.11.4. When using the memory engine, it is possible to store a nested JSON representation of the configuration. The .set() function, that is responsible for setting the configuration properties, is vulnerable to Prototype Pollution. By providing a crafted property, it is possible to modify the properties on the Object.prototype.",
  "id": "GHSA-6xwr-q98w-rvg7",
  "modified": "2022-04-22T20:32:05Z",
  "published": "2022-04-13T00:00:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-21803"
    },
    {
      "type": "WEB",
      "url": "https://github.com/indexzero/nconf/pull/397"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/indexzero/nconf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/indexzero/nconf/releases/tag/v0.11.4"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-NCONF-2395478"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Prototype Pollution in nconf"
}

GHSA-72XF-G2V4-QVF3

Vulnerability from github – Published: 2023-07-01 06:30 – Updated: 2024-06-21 21:33

Summary

tough-cookie Prototype Pollution vulnerability

Details

Versions of the package tough-cookie before 4.1.3 are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in rejectPublicSuffixes=false mode. This issue arises from the manner in which the objects are initialized.

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "tough-cookie"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-26136"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-07-07T21:39:57Z",
    "nvd_published_at": "2023-07-01T05:15:16Z",
    "severity": "MODERATE"
  },
  "details": "Versions of the package tough-cookie before 4.1.3 are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in `rejectPublicSuffixes=false` mode. This issue arises from the manner in which the objects are initialized.",
  "id": "GHSA-72xf-g2v4-qvf3",
  "modified": "2024-06-21T21:33:53Z",
  "published": "2023-07-01T06:30:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-26136"
    },
    {
      "type": "WEB",
      "url": "https://github.com/salesforce/tough-cookie/issues/282"
    },
    {
      "type": "WEB",
      "url": "https://github.com/salesforce/tough-cookie/commit/12d474791bb856004e858fdb1c47b7608d09cf6e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/salesforce/tough-cookie"
    },
    {
      "type": "WEB",
      "url": "https://github.com/salesforce/tough-cookie/releases/tag/v4.1.3"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/07/msg00010.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3HUE6ZR5SL73KHL7XUPAOEL6SB7HUDT2"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6PVVPNSAGSDS63HQ74PJ7MZ3MU5IYNVZ"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20240621-0006"
    },
    {
      "type": "WEB",
      "url": "https://security.snyk.io/vuln/SNYK-JS-TOUGHCOOKIE-5672873"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "tough-cookie Prototype Pollution vulnerability"
}

GHSA-7358-GFXQ-387J

Vulnerability from github – Published: 2024-08-29 03:30 – Updated: 2024-08-29 21:31

Details

Chartist 1.x through 1.3.0 allows Prototype Pollution via the extend function.

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2024-45435"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-08-29T03:15:05Z",
    "severity": "CRITICAL"
  },
  "details": "Chartist 1.x through 1.3.0 allows Prototype Pollution via the extend function.",
  "id": "GHSA-7358-gfxq-387j",
  "modified": "2024-08-29T21:31:03Z",
  "published": "2024-08-29T03:30:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-45435"
    },
    {
      "type": "WEB",
      "url": "https://github.com/chartist-js/chartist/issues/1427"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/tariqhawis/c67177164d3b7975210caddb25b60d62"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-737V-MQG7-C878

Vulnerability from github – Published: 2026-04-04 06:17 – Updated: 2026-04-06 23:42

Summary

defu: Prototype pollution via `__proto__` key in defaults argument

Details

Impact

Applications that pass unsanitized user input (e.g. parsed JSON request bodies, database records, or config files from untrusted sources) as the first argument to defu() are vulnerable to prototype pollution.

A crafted payload containing a __proto__ key can override intended default values in the merged result:

import { defu } from 'defu'

const userInput = JSON.parse('{"__proto__":{"isAdmin":true}}')
const config = defu(userInput, { isAdmin: false })

config.isAdmin // true — attacker overrides the server default

Root Cause

The internal _defu function used Object.assign({}, defaults) to copy the defaults object. Object.assign invokes the __proto__ setter, which replaces the resulting object's [[Prototype]] with attacker-controlled values. Properties inherited from the polluted prototype then bypass the existing __proto__ key guard in the for...in loop and land in the final result.

Fix

Replace Object.assign({}, defaults) with object spread ({ ...defaults }), which uses [[DefineOwnProperty]] and does not invoke the __proto__ setter.

Affected Versions

<= 6.1.4

Credits

Reported by @BlackHatExploitation

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 6.1.4"
      },
      "package": {
        "ecosystem": "npm",
        "name": "defu"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-35209"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-04T06:17:53Z",
    "nvd_published_at": "2026-04-06T18:16:44Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nApplications that pass unsanitized user input (e.g. parsed JSON request bodies, database records, or config files from untrusted sources) as the first argument to `defu()` are vulnerable to prototype pollution.\n\nA crafted payload containing a `__proto__` key can override intended default values in the merged result:\n\n```js\nimport { defu } from \u0027defu\u0027\n\nconst userInput = JSON.parse(\u0027{\"__proto__\":{\"isAdmin\":true}}\u0027)\nconst config = defu(userInput, { isAdmin: false })\n\nconfig.isAdmin // true \u2014 attacker overrides the server default\n```\n\n### Root Cause\n\nThe internal `_defu` function used `Object.assign({}, defaults)` to copy the defaults object. `Object.assign` invokes the `__proto__` setter, which replaces the resulting object\u0027s `[[Prototype]]` with attacker-controlled values. Properties inherited from the polluted prototype then bypass the existing `__proto__` key guard in the `for...in` loop and land in the final result.\n\n### Fix\n\nReplace `Object.assign({}, defaults)` with object spread (`{ ...defaults }`), which uses `[[DefineOwnProperty]]` and does not invoke the `__proto__` setter.\n\n### Affected Versions\n\n\u003c= 6.1.4\n\n### Credits\n\nReported by [@BlackHatExploitation](https://github.com/BlackHatExploitation)",
  "id": "GHSA-737v-mqg7-c878",
  "modified": "2026-04-06T23:42:28Z",
  "published": "2026-04-04T06:17:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/unjs/defu/security/advisories/GHSA-737v-mqg7-c878"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-35209"
    },
    {
      "type": "WEB",
      "url": "https://github.com/unjs/defu/pull/156"
    },
    {
      "type": "WEB",
      "url": "https://github.com/unjs/defu/commit/3942bfbbcaa72084bd4284846c83bd61ed7c8b29"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/unjs/defu"
    },
    {
      "type": "WEB",
      "url": "https://github.com/unjs/defu/releases/tag/v6.1.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "defu: Prototype pollution via `__proto__` key in defaults argument"
}

GHSA-73WF-GQ98-2V4G

Vulnerability from github – Published: 2026-09-01 16:41 – Updated: 2026-09-01 16:41

Summary

Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)

Details

Vulnerability Details

File: node.js Function: normalizeStats() (line ~214), reached from getStat() (called unconditionally on every browserslist() call) and loadStat()

Root Cause

function normalizeStats(data, stats) {
  if (!data) { data = {} }
  if (stats && 'dataByBrowser' in stats) { stats = stats.dataByBrowser }
  if (typeof stats !== 'object') return undefined

  var normalized = {}
  for (var i in stats) {
    var versions = Object.keys(stats[i])
    if (versions.length === 1 && data[i] && data[i].versions.length === 1) {
      var normal = data[i].versions[0]
      normalized[i] = {}
      normalized[i][normal] = stats[i][versions[0]]
    } else {
      normalized[i] = stats[i]
    }
  }
  return normalized
}

stats is untrusted: it comes from JSON.parse()-ing a browserslist-stats.json file — auto-discovered by walking up the directory tree from the project root on every browserslist() call, regardless of the query (env.getStat(opts, browserslist.data) runs unconditionally inside browserslist()) — or from opts.stats passed programmatically / via the CLI's --stats= flag. data is browserslist.data, a plain object populated only with real browser names.

Two independent bugs from the same root cause (unguarded for...in over untrusted keys used with plain-object bracket access/assignment):

Crash: data[i] has no hasOwnProperty guard. If stats contains a key that also happens to be an inherited Object.prototype member name — "__proto__", "toString", "valueOf", "constructor", "hasOwnProperty", "isPrototypeOf", etc. — data[i] resolves to that inherited function/object (always truthy), and the code then does data[i].versions.length → undefined.length → uncaught TypeError, for any such key whose JSON value has exactly one sub-key, e.g.: json { "toString": { "onekey": 5 }, "chrome": { "100": 50 } }
Prototype write: normalized[i] = ... on the fresh normalized = {} — if i is exactly "__proto__" (and normalized has no own property by that name yet), this computed assignment invokes the real Object.prototype.__proto__ setter, changing normalized's actual [[Prototype]] instead of creating a plain property.

Because this runs on every browserslist() call regardless of the query, simply committing a poisoned browserslist-stats.json anywhere in a project's directory tree breaks every subsequent Browserslist call in that project — including calls made by Autoprefixer, Babel preset-env, Stylelint, or PostCSS internally, for completely unrelated queries.

Attack Scenario

Attacker submits a PR (or a compromised dependency) adding a browserslist-stats.json file anywhere between the project root and filesystem root, containing e.g. {"toString": {"onekey": 5}, "chrome": {"100": 50}}.
The victim's build/CI pipeline runs any tool that calls browserslist() internally, for any query.
The auto-discovered poisoned file crashes the process with an uncaught TypeError on the very first call.

Measured Impact

Confirmed crash (real browserslist() call, v4.28.6) with stats keys: __proto__, toString, valueOf, hasOwnProperty, constructor, isPrototypeOf — each paired with a one-key JSON object — for any query, including browserslist('defaults') which never mentions stats.

Recommended Fix (implemented and verified)

var normalized = Object.create(null)
for (var i in stats) {
  var versions = Object.keys(stats[i])
  var known = Object.prototype.hasOwnProperty.call(data, i) && data[i]
  if (versions.length === 1 && known && known.versions.length === 1) {
    var normal = known.versions[0]
    normalized[i] = Object.create(null)
    normalized[i][normal] = stats[i][versions[0]]
  } else {
    normalized[i] = stats[i]
  }
}
return normalized

normalized uses Object.create(null) so a write to "__proto__" is an ordinary property set, never a [[Prototype]] change; data[i] is replaced with an explicit hasOwnProperty check so it never resolves to an inherited Object.prototype member.

Verification: - NODE_ENV=test npx uvu test .test.js → 301/301 pass unmodified (test/custom.test.js, test/shareable-stats.test.js, test/cover.test.js exercise the stats-handling paths). - All 6 previously crash-inducing keys, tested individually, now resolve without error. - The realistic file-based auto-discovery scenario (poisoned browserslist-stats.json + an unrelated browserslist('defaults') call) now returns a normal result instead of crashing.

Impact

Who is affected: Any project whose build/CI invokes Browserslist (directly or via Autoprefixer/Babel/Stylelint/PostCSS) in a directory tree an attacker can place a file into (external PR, compromised dependency), or any app that passes user-influenced data into opts.stats.
What an attacker achieves: Immediate DoS — crashes the invoking process on the first Browserslist call after the file is present, for any query, no special syntax needed.
Conditions required: No authentication — only the ability to add a file to the project's directory tree, or influence opts.stats.

Verification Environment

browserslist @ HEAD (== v4.28.6, current latest stable release) under local Node.js v20.19.5. Pure JS library — executed directly, no server needed.

Note

Found via a systematic review of prototype-pollution-adjacent patterns in this codebase after confirming two unrelated algorithmic-complexity issues (reported separately as GHSA-rrmg-cfrq-23vv and GHSA-g6p8-hj8g-x889) in the same research pass. A similar for...in + bracket-write pattern in index.js's copyObject() (used by normalizeAndroidData) was already guarded against __proto__/constructor/prototype keys by a prior, unrelated commit — that guard was never applied to this function.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.28.6"
      },
      "package": {
        "ecosystem": "npm",
        "name": "browserslist"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.28.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-73088"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-248"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-01T16:41:54Z",
    "nvd_published_at": "2026-08-11T17:19:16Z",
    "severity": "HIGH"
  },
  "details": "## Vulnerability Details\n\n**File**: `node.js`\n**Function**: `normalizeStats()` (line ~214), reached from `getStat()` (called\n**unconditionally** on every `browserslist()` call) and `loadStat()`\n\n### Root Cause\n```js\nfunction normalizeStats(data, stats) {\n  if (!data) { data = {} }\n  if (stats \u0026\u0026 \u0027dataByBrowser\u0027 in stats) { stats = stats.dataByBrowser }\n  if (typeof stats !== \u0027object\u0027) return undefined\n\n  var normalized = {}\n  for (var i in stats) {\n    var versions = Object.keys(stats[i])\n    if (versions.length === 1 \u0026\u0026 data[i] \u0026\u0026 data[i].versions.length === 1) {\n      var normal = data[i].versions[0]\n      normalized[i] = {}\n      normalized[i][normal] = stats[i][versions[0]]\n    } else {\n      normalized[i] = stats[i]\n    }\n  }\n  return normalized\n}\n```\n`stats` is untrusted: it comes from `JSON.parse()`-ing a\n`browserslist-stats.json` file \u2014 auto-discovered by walking up the directory\ntree from the project root **on every `browserslist()` call, regardless of\nthe query** (`env.getStat(opts, browserslist.data)` runs unconditionally\ninside `browserslist()`) \u2014 or from `opts.stats` passed programmatically /\nvia the CLI\u0027s `--stats=` flag. `data` is `browserslist.data`, a plain object\npopulated only with real browser names.\n\nTwo independent bugs from the same root cause (unguarded `for...in` over\nuntrusted keys used with plain-object bracket access/assignment):\n\n1. **Crash**: `data[i]` has no `hasOwnProperty` guard. If `stats` contains a\n   key that also happens to be an inherited `Object.prototype` member name \u2014\n   `\"__proto__\"`, `\"toString\"`, `\"valueOf\"`, `\"constructor\"`,\n   `\"hasOwnProperty\"`, `\"isPrototypeOf\"`, etc. \u2014 `data[i]` resolves to that\n   inherited function/object (always truthy), and the code then does\n   `data[i].versions.length` \u2192 `undefined.length` \u2192 **uncaught `TypeError`**,\n   for any such key whose JSON value has exactly one sub-key, e.g.:\n   ```json\n   { \"toString\": { \"onekey\": 5 }, \"chrome\": { \"100\": 50 } }\n   ```\n2. **Prototype write**: `normalized[i] = ...` on the fresh\n   `normalized = {}` \u2014 if `i` is exactly `\"__proto__\"` (and `normalized` has\n   no own property by that name yet), this computed assignment invokes the\n   real `Object.prototype.__proto__` setter, changing `normalized`\u0027s actual\n   `[[Prototype]]` instead of creating a plain property.\n\nBecause this runs on **every** `browserslist()` call regardless of the\nquery, simply committing a poisoned `browserslist-stats.json` anywhere in a\nproject\u0027s directory tree breaks every subsequent Browserslist call in that\nproject \u2014 including calls made by Autoprefixer, Babel `preset-env`,\nStylelint, or PostCSS internally, for completely unrelated queries.\n\n### Attack Scenario\n1. Attacker submits a PR (or a compromised dependency) adding a\n   `browserslist-stats.json` file anywhere between the project root and\n   filesystem root, containing e.g.\n   `{\"toString\": {\"onekey\": 5}, \"chrome\": {\"100\": 50}}`.\n2. The victim\u0027s build/CI pipeline runs any tool that calls `browserslist()`\n   internally, for **any** query.\n3. The auto-discovered poisoned file crashes the process with an uncaught\n   `TypeError` on the very first call.\n\n### Measured Impact\nConfirmed crash (real `browserslist()` call, v4.28.6) with `stats` keys:\n`__proto__`, `toString`, `valueOf`, `hasOwnProperty`, `constructor`,\n`isPrototypeOf` \u2014 each paired with a one-key JSON object \u2014 for any query,\nincluding `browserslist(\u0027defaults\u0027)` which never mentions stats.\n\n### Recommended Fix (implemented and verified)\n```js\nvar normalized = Object.create(null)\nfor (var i in stats) {\n  var versions = Object.keys(stats[i])\n  var known = Object.prototype.hasOwnProperty.call(data, i) \u0026\u0026 data[i]\n  if (versions.length === 1 \u0026\u0026 known \u0026\u0026 known.versions.length === 1) {\n    var normal = known.versions[0]\n    normalized[i] = Object.create(null)\n    normalized[i][normal] = stats[i][versions[0]]\n  } else {\n    normalized[i] = stats[i]\n  }\n}\nreturn normalized\n```\n`normalized` uses `Object.create(null)` so a write to `\"__proto__\"` is an\nordinary property set, never a `[[Prototype]]` change; `data[i]` is replaced\nwith an explicit `hasOwnProperty` check so it never resolves to an inherited\n`Object.prototype` member.\n\n**Verification**:\n- `NODE_ENV=test npx uvu test .test.js` \u2192 301/301 pass unmodified\n  (`test/custom.test.js`, `test/shareable-stats.test.js`, `test/cover.test.js`\n  exercise the stats-handling paths).\n- All 6 previously crash-inducing keys, tested individually, now resolve\n  without error.\n- The realistic file-based auto-discovery scenario (poisoned\n  `browserslist-stats.json` + an unrelated `browserslist(\u0027defaults\u0027)` call)\n  now returns a normal result instead of crashing.\n\n### Impact\n- **Who is affected**: Any project whose build/CI invokes Browserslist\n  (directly or via Autoprefixer/Babel/Stylelint/PostCSS) in a directory tree\n  an attacker can place a file into (external PR, compromised dependency),\n  or any app that passes user-influenced data into `opts.stats`.\n- **What an attacker achieves**: Immediate DoS \u2014 crashes the invoking\n  process on the first Browserslist call after the file is present, for any\n  query, no special syntax needed.\n- **Conditions required**: No authentication \u2014 only the ability to add a\n  file to the project\u0027s directory tree, or influence `opts.stats`.\n\n### Verification Environment\nbrowserslist @ HEAD (== v4.28.6, current latest stable release) under local\nNode.js v20.19.5. Pure JS library \u2014 executed directly, no server needed.\n\n### Note\nFound via a systematic review of prototype-pollution-adjacent patterns in\nthis codebase after confirming two unrelated algorithmic-complexity issues\n(reported separately as GHSA-rrmg-cfrq-23vv and GHSA-g6p8-hj8g-x889) in the\nsame research pass. A similar `for...in` + bracket-write pattern in\n`index.js`\u0027s `copyObject()` (used by `normalizeAndroidData`) was already\nguarded against `__proto__`/`constructor`/`prototype` keys by a prior,\nunrelated commit \u2014 that guard was never applied to this function.",
  "id": "GHSA-73wf-gq98-2v4g",
  "modified": "2026-09-01T16:41:54Z",
  "published": "2026-09-01T16:41:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/browserslist/browserslist/security/advisories/GHSA-73wf-gq98-2v4g"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73088"
    },
    {
      "type": "WEB",
      "url": "https://github.com/browserslist/browserslist/commit/f9914ad9effc865ccc27d816255625890b31ca51"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/browserslist/browserslist"
    },
    {
      "type": "WEB",
      "url": "https://github.com/browserslist/browserslist/releases/tag/4.28.7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)"
}

GHSA-74CR-77XC-8G6R

Vulnerability from github – Published: 2019-06-13 20:37 – Updated: 2021-08-16 15:28

Summary

Prototype Pollution in @apollo/gateway

Details

Versions of @apollo/gateway prior to 0.6.2 are vulnerable to Prototype Pollution. The package uses deepMerge() to merge objects, which may allow attackers to alter the Object prototype through queries with GraphQL aliases. Carefully constructed payloads can override properties of all objects in the application. This may lead to Denial of Service or may be chained with other vulnerabilities leading to Remote Code Execution.

Recommendation

Upgrade to version 0.6.2 or later.

Severity

7.3 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@apollo/gateway"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.6.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2019-06-13T20:37:08Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "Versions of `@apollo/gateway` prior to 0.6.2 are vulnerable to Prototype Pollution. The package uses deepMerge() to merge objects, which may allow attackers to alter the Object prototype through queries with GraphQL aliases. Carefully constructed payloads can override properties of all objects in the application. This may lead to Denial of Service or may be chained with other vulnerabilities leading to Remote Code Execution.\n\n\n## Recommendation\n\nUpgrade to version 0.6.2 or later.\n",
  "id": "GHSA-74cr-77xc-8g6r",
  "modified": "2021-08-16T15:28:22Z",
  "published": "2019-06-13T20:37:39Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/apollographql/apollo-server/pull/2779"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apollographql/apollo-server/commit/cea7397582a293af6a5f60947da34b95e669c6c1"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-APOLLOGATEWAY-174915"
    },
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/917"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Prototype Pollution in @apollo/gateway"
}

GHSA-75MV-GP69-2CQM

Vulnerability from github – Published: 2022-05-24 16:58 – Updated: 2022-12-02 21:30

Details

SugarCRM before 8.0.4 and 9.x before 9.0.2 allows PHP object injection in the Administration module by an Admin user.

Severity

7.2 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2019-17315"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-10-07T15:15:00Z",
    "severity": "MODERATE"
  },
  "details": "SugarCRM before 8.0.4 and 9.x before 9.0.2 allows PHP object injection in the Administration module by an Admin user.",
  "id": "GHSA-75mv-gp69-2cqm",
  "modified": "2022-12-02T21:30:46Z",
  "published": "2022-05-24T16:58:08Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-17315"
    },
    {
      "type": "WEB",
      "url": "https://support.sugarcrm.com/Resources/Security/sugarcrm-sa-2019-042"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-75PX-5XX7-5XC7

Vulnerability from github – Published: 2026-05-12 15:01 – Updated: 2026-05-14 20:35

Summary

protobuf.js: Code generation gadget after prototype pollution

Details

Summary

protobufjs used plain objects with inherited prototypes for internal type lookup tables used by generated encode and decode functions. If Object.prototype had already been polluted, those lookup tables could resolve attacker-controlled inherited properties as valid protobuf type information.

This could cause attacker-controlled strings to be emitted into generated JavaScript code.

Impact

An attacker who can first trigger a prototype pollution vulnerability may be able to influence generated protobufjs encode or decode functions in a way that can lead to arbitrary JavaScript execution.

This issue requires a separate prototype pollution primitive before protobufjs is invoked.

Applications without a reachable prototype pollution primitive are not directly exploitable through this issue alone.

Preconditions

The application or one of its dependencies must allow an attacker to pollute Object.prototype.
The polluted property must affect protobufjs internal type lookup behavior.
The application must use protobufjs functionality that generates encode or decode code for affected types.
The generated code path must be reached after the prototype pollution has occurred.

Workarounds

Avoid running affected versions in applications where attacker-controlled input can pollute Object.prototype. If immediate upgrade is not possible, remove or mitigate reachable prototype pollution primitives and isolate schema/message processing from untrusted application state.

Severity

8.1 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 7.5.5"
      },
      "package": {
        "ecosystem": "npm",
        "name": "protobufjs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.5.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 8.0.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "protobufjs"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44291"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-12T15:01:24Z",
    "nvd_published_at": "2026-05-13T16:16:55Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nprotobufjs used plain objects with inherited prototypes for internal type lookup tables used by generated encode and decode functions. If `Object.prototype` had already been polluted, those lookup tables could resolve attacker-controlled inherited properties as valid protobuf type information.\n\nThis could cause attacker-controlled strings to be emitted into generated JavaScript code.\n\n## Impact\n\nAn attacker who can first trigger a prototype pollution vulnerability may be able to influence generated protobufjs encode or decode functions in a way that can lead to arbitrary JavaScript execution.\n\nThis issue requires a separate prototype pollution primitive before protobufjs is invoked.\n\nApplications without a reachable prototype pollution primitive are not directly exploitable through this issue alone.\n\n## Preconditions\n\n- The application or one of its dependencies must allow an attacker to pollute `Object.prototype`.\n- The polluted property must affect protobufjs internal type lookup behavior.\n- The application must use protobufjs functionality that generates encode or decode code for affected types.\n- The generated code path must be reached after the prototype pollution has occurred.\n\n## Workarounds\n\nAvoid running affected versions in applications where attacker-controlled input can pollute `Object.prototype`. If immediate upgrade is not possible, remove or mitigate reachable prototype pollution primitives and isolate schema/message processing from untrusted application state.",
  "id": "GHSA-75px-5xx7-5xc7",
  "modified": "2026-05-14T20:35:15Z",
  "published": "2026-05-12T15:01:24Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-75px-5xx7-5xc7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44291"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/protobufjs/protobuf.js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v7.5.6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.0.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "protobuf.js: Code generation gadget after prototype pollution"
}

GHSA-75QM-GP28-RCQ9

Vulnerability from github – Published: 2026-07-22 21:57 – Updated: 2026-07-22 21:57

Summary

n8n: Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration

Details

Impact

An authenticated user with the default workflow:create permission could pollute Object.prototype through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account's personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted.

Patches

The issue has been fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict workflow creation and editing permissions to fully trusted users only. - Restrict network access to the n8n instance to trusted users only.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Severity

7.1 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.123.61"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.28.0"
            },
            {
              "fixed": "2.28.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0-rc.0"
            },
            {
              "fixed": "2.27.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59206"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-22T21:57:21Z",
    "nvd_published_at": "2026-07-09T16:16:46Z",
    "severity": "HIGH"
  },
  "details": "## Impact\nAn authenticated user with the default `workflow:create` permission could pollute `Object.prototype` through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account\u0027s personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted.\n\n## Patches\nThe issue has been fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict workflow creation and editing permissions to fully trusted users only.\n- Restrict network access to the n8n instance to trusted users only.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
  "id": "GHSA-75qm-gp28-rcq9",
  "modified": "2026-07-22T21:57:21Z",
  "published": "2026-07-22T21:57:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-75qm-gp28-rcq9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59206"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/n8n-io/n8n"
    },
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/releases/tag/n8n%402.27.4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/releases/tag/n8n%402.28.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "n8n: Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration"
}

GHSA-765H-QJXV-5F44

Vulnerability from github – Published: 2022-02-10 23:51 – Updated: 2023-11-29 20:30

Summary

Prototype Pollution in handlebars

Details

The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "handlebars"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.7.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-23383"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-05-19T21:17:59Z",
    "nvd_published_at": "2021-05-04T09:15:00Z",
    "severity": "CRITICAL"
  },
  "details": "The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.",
  "id": "GHSA-765h-qjxv-5f44",
  "modified": "2023-11-29T20:30:56Z",
  "published": "2022-02-10T23:51:42Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-23383"
    },
    {
      "type": "WEB",
      "url": "https://github.com/handlebars-lang/handlebars.js/commit/f0589701698268578199be25285b2ebea1c1e427"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/handlebars-lang/handlebars.js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/handlebars-source/CVE-2021-23383.yml"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20210618-0007"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARS-1279031"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWER-1279032"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1279030"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-HANDLEBARS-1279029"
    },
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/package/handlebars"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Prototype Pollution in handlebars"
}

Mitigation

Implementation

By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.

Mitigation

Architecture and Design

By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.

Mitigation

Implementation

Strategy: Input Validation

When handling untrusted objects, validating using a schema can be used.

Mitigation

Implementation

By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.

Mitigation

Implementation

Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.

CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs

In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.

CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels

An attacker exploits a weakness in the configuration of access controls and is able to bypass the intended protection that these measures guard against and thereby obtain unauthorized access to the system or network. Sensitive functionality should always be protected with access controls. However configuring all but the most trivial access control systems can be very complicated and there are many opportunities for mistakes. If an attacker can learn of incorrectly configured access security settings, they may be able to exploit this in an attack.

CAPEC-77: Manipulating User-Controlled Variables

This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An adversary can override variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the adversary can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.

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