{"id":"GHSA-xrf2-5r3p-5wgj","aliases":["RUSTSEC-2026-0076"],"url":"https://o3.security/vulnerability/GHSA-xrf2-5r3p-5wgj","summary":"libcrux: Panic in Signature Hint Decoding During Verification","details":"During ML-DSA verification the serialized hint values are decoded as specified in algorithm 22 `HintBitUnpack` of [FIPS 204, subsection 7.1](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#%5B%7B%22num%22%3A120%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22FitH%22%7D%2C657%5D). The algorithm requires that the cumulative hint counters per row of the hint vector are strictly increasing and below a maximum value which depends on the choice of ML-DSA parameter set (line 4).\n\nIn libcrux-ml-dsa, hint decoding did not check the boundedness of the cumulative hint counter of the last row of the hint vector.\n\n## Impact\nA manipulated invalid hint can cause an out-of-bounds memory access since the hint decoding logic may attempt to read outside the bounds of the serialized signature, causing a runtime panic.\n\n## Mitigation\nStarting from version `0.0.8`, hint decoding will check the cumulative hint counter of the last row as well.","published":"2026-03-26T17:58:16Z","modified":"2026-03-27T06:11:21.325253Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"libcrux-ml-dsa","fixedVersion":"0.0.8"}],"fix":{"url":"https://github.com/cryspen/libcrux/pull/1348","label":"cryspen/libcrux#1348"},"references":[{"type":"WEB","url":"https://github.com/cryspen/libcrux/pull/1348"},{"type":"PACKAGE","url":"https://github.com/cryspen/libcrux"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2026-0076.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-03-27T06:11:21.325253Z"}}