GHSA-W5HQ-G745-H8PQ

Vulnerability from github – Published: 2026-04-22 20:53 – Updated: 2026-05-21 18:25
VLAI
Summary
uuid: Missing buffer bounds check in v3/v5/v6 when buf is provided
Details

Summary

The v3(), v5(), and v6() API methods (not uuid release versions) accept external output buffers but do not reject out-of-range writes (small buf or large offset).
By contrast, v4(), v1(), and v7() API methods explicitly throw RangeError on invalid bounds.

This inconsistency allows silent partial writes into caller-provided buffers.

Affected code

  • src/v35.ts (v3()/v5() path) writes buf[offset + i] without bounds validation.
  • src/v6.ts writes buf[offset + i] without bounds validation.

Reproducible PoC

cd /home/StrawHat/uuid
npm ci
npm run build

node --input-type=module -e "
import {v4,v5,v6} from './dist-node/index.js';
const ns='6ba7b810-9dad-11d1-80b4-00c04fd430c8';
for (const [name,fn] of [
  ['v4()',()=>v4({},new Uint8Array(8),4)],
  ['v5()',()=>v5('x',ns,new Uint8Array(8),4)],
  ['v6()',()=>v6({},new Uint8Array(8),4)],
]) {
  try { fn(); console.log(name,'NO_THROW'); }
  catch(e){ console.log(name,'THREW',e.name); }
}"

Observed:

  • v4() THREW RangeError
  • v5() NO_THROW
  • v6() NO_THROW

Example partial overwrite evidence captured during audit:

same true buf [
  170, 170, 170, 170,
   75, 224, 100,  63
]
v6 [
  187, 187, 187, 187,
   31,  19, 185,  64
]

Security impact

  • Primary: integrity/robustness issue (silent partial output).
  • If an application assumes full UUID writes into preallocated buffers, this can produce malformed/truncated/partially stale identifiers without error.
  • In systems where caller-controlled offsets/buffer sizes are exposed indirectly, this may become a security-relevant logic flaw.

Suggested fix

Add the same guard used by v4()/v1()/v7():

if (offset < 0 || offset + 16 > buf.length) {
  throw new RangeError(`UUID byte range ${offset}:${offset + 15} is out of buffer bounds`);
}

Apply to:

  • src/v35.ts (covers v3() and v5())
  • src/v6.ts
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "uuid"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "11.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "uuid"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "12.0.0"
            },
            {
              "fixed": "12.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "uuid"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "13.0.0"
            },
            {
              "fixed": "13.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-41907"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1285",
      "CWE-787"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-22T20:53:24Z",
    "nvd_published_at": "2026-04-24T19:17:14Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe `v3()`, `v5()`, and `v6()` [API methods](https://github.com/uuidjs/uuid#api-summary) (not `uuid` release versions) accept external output buffers but do not reject out-of-range writes (small `buf` or large `offset`).  \nBy contrast, `v4()`, `v1()`, and `v7()` API methods explicitly throw `RangeError` on invalid bounds.\n\nThis inconsistency allows **silent partial writes** into caller-provided buffers.\n\n\n### Affected code\n\n- `src/v35.ts` (`v3()`/`v5()` path) writes `buf[offset + i]` without bounds validation.\n- `src/v6.ts` writes `buf[offset + i]` without bounds validation.\n\n### Reproducible PoC\n\n```bash\ncd /home/StrawHat/uuid\nnpm ci\nnpm run build\n\nnode --input-type=module -e \"\nimport {v4,v5,v6} from \u0027./dist-node/index.js\u0027;\nconst ns=\u00276ba7b810-9dad-11d1-80b4-00c04fd430c8\u0027;\nfor (const [name,fn] of [\n  [\u0027v4()\u0027,()=\u003ev4({},new Uint8Array(8),4)],\n  [\u0027v5()\u0027,()=\u003ev5(\u0027x\u0027,ns,new Uint8Array(8),4)],\n  [\u0027v6()\u0027,()=\u003ev6({},new Uint8Array(8),4)],\n]) {\n  try { fn(); console.log(name,\u0027NO_THROW\u0027); }\n  catch(e){ console.log(name,\u0027THREW\u0027,e.name); }\n}\"\n```\n\nObserved:\n\n- `v4() THREW RangeError`\n- `v5() NO_THROW`\n- `v6() NO_THROW`\n\nExample partial overwrite evidence captured during audit:\n\n```text\nsame true buf [\n  170, 170, 170, 170,\n   75, 224, 100,  63\n]\nv6 [\n  187, 187, 187, 187,\n   31,  19, 185,  64\n]\n```\n\n### Security impact\n\n- **Primary**: integrity/robustness issue (silent partial output).\n- If an application assumes full UUID writes into preallocated buffers, this can produce malformed/truncated/partially stale identifiers without error.\n- In systems where caller-controlled offsets/buffer sizes are exposed indirectly, this may become a security-relevant logic flaw.\n\n### Suggested fix\n\nAdd the same guard used by `v4()`/`v1()`/`v7()`:\n\n```ts\nif (offset \u003c 0 || offset + 16 \u003e buf.length) {\n  throw new RangeError(`UUID byte range ${offset}:${offset + 15} is out of buffer bounds`);\n}\n```\n\nApply to:\n\n- `src/v35.ts` (covers `v3()` and `v5()`)\n- `src/v6.ts`",
  "id": "GHSA-w5hq-g745-h8pq",
  "modified": "2026-05-21T18:25:56Z",
  "published": "2026-04-22T20:53:24Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/security/advisories/GHSA-w5hq-g745-h8pq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-41907"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/commit/32389c887c9e75f90442ee4cc95bbab0c4e8346e"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/commit/3d2c5b0342f0fcb52a5ac681c3d47c13e7444b34"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/commit/3d61d6ac1f782cf6b1dd8661c60f11722cd49a0d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/commit/9d27ddf7046ce496ef39569ff84d948eeff9cb2a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/uuidjs/uuid"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/releases/tag/v11.1.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/releases/tag/v12.0.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/releases/tag/v13.0.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/uuidjs/uuid/releases/tag/v14.0.0"
    }
  ],
  "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"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "uuid: Missing buffer bounds check in v3/v5/v6 when buf is provided"
}


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