{"id":"GHSA-xrf2-5r3p-5wgj","aliases":["RUSTSEC-2026-0076"],"status":"published","title":"libcrux: Panic in Signature Hint Decoding During Verification","description":"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.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","from":"ghsa"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-125","CWE-1285"],"published":"2026-03-04T12:00:00Z","modified":"2026-03-27T06:11:21Z","fixes":[{"ecosystem":"crates.io","package":"libcrux-ml-dsa","fixed_in":["0.0.8"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"libcrux-ml-dsa","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.0.8"}]}]},{"source":"osv","ecosystem":"crates.io","package":"libcrux-ml-dsa","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.8"}]}]},{"source":"osv","ecosystem":"crates.io","package":"libcrux-ml-dsa","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.0.8"}]}]}],"references":[{"url":"https://github.com/cryspen/libcrux/pull/1348","tags":["web"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0076.html","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-xrf2-5r3p-5wgj"},{"url":"https://github.com/cryspen/libcrux","tags":["package"]},{"url":"https://crates.io/crates/libcrux-ml-dsa","tags":["package"]}],"sources":{"ghsa":[{"id":"GHSA-xrf2-5r3p-5wgj","title":"libcrux: Panic in Signature Hint Decoding During Verification","description":"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.","status":"published","published":"2026-03-26T17:58:16Z","modified":"2026-03-26T17:58:16Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-125","CWE-1285"],"updated_at":"2026-11-02T14:39:42.712607Z"}],"osv":[{"id":"GHSA-xrf2-5r3p-5wgj","title":"libcrux: Panic in Signature Hint Decoding During Verification","description":"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.","status":"published","published":"2026-03-26T17:58:16Z","modified":"2026-03-27T06:11:21.325253Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-125","CWE-1285"],"updated_at":"2026-11-02T15:47:00.198893Z"},{"id":"RUSTSEC-2026-0076","title":"Panic in Signature Hint Decoding During Verification","description":"During ML-DSA verification the serialized hint values are decoded as\nspecified in algorithm 22 `HintBitUnpack` of [FIPS 204, subsection\n7.1](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\nalgorithm requires that the cumulative hint counters per row of the\nhint vector are strictly increasing and below a maximum value which\ndepends on the choice of ML-DSA parameter set (line 4).\n\nIn libcrux-ml-dsa, hint decoding did not check the boundedness of the\ncumulative 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\nsince the hint decoding logic may attempt to read outside the bounds\nof the serialized signature, causing a runtime panic.\n\n## Mitigation\nStarting from version `0.0.8`, hint decoding will check the cumulative\nhint counter of the last row as well.","status":"published","published":"2026-03-04T12:00:00Z","modified":"2026-03-27T05:55:06Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T15:53:40.430679Z"}]}}