{"id":"CVE-2026-41907","aliases":["CVE-2026-41988","GHSA-w5hq-g745-h8pq"],"url":"https://o3.security/vulnerability/CVE-2026-41907","summary":"uuid: Missing buffer bounds check in `v3`/`v5`/`v6` when `buf` is provided","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 './dist-node/index.js';\nconst ns='6ba7b810-9dad-11d1-80b4-00c04fd430c8';\nfor (const [name,fn] of [\n  ['v4()',()=>v4({},new Uint8Array(8),4)],\n  ['v5()',()=>v5('x',ns,new Uint8Array(8),4)],\n  ['v6()',()=>v6({},new Uint8Array(8),4)],\n]) {\n  try { fn(); console.log(name,'NO_THROW'); }\n  catch(e){ console.log(name,'THREW',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 < 0 || offset + 16 > 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`","published":"2026-04-24T18:09:24.744Z","modified":"2026-10-28T02:31:14.607312456Z","cvss":null,"epss":{"score":0.00337,"percentile":0.26481,"asOf":"2026-08-13"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"uuid","fixedVersion":"11.1.1"},{"ecosystem":"npm","name":"uuid","fixedVersion":"12.0.1"},{"ecosystem":"npm","name":"uuid","fixedVersion":"13.0.1"}],"fix":{"url":"https://github.com/uuidjs/uuid/commit/32389c887c9e75f90442ee4cc95bbab0c4e8346e","label":"uuidjs/uuid@32389c8"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41907.json"},{"type":"ADVISORY","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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:14.607312456Z"}}