{"id":"GHSA-cp57-fq8g-qh6v","aliases":["RUSTSEC-2026-0077"],"status":"published","title":"libcrux has an Incorrect Check of Signer Response Norm During Verification","description":"The ML-DSA verification algorithm as specified in [FIPS 204, subsection 6.3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#subsection.6.3) requires verifiers to check that the infinity norm of the deserialized signer response $z$ does not exceed $\\gamma_1 - \\beta$ (line 13 of Algorithm 8). The same check is required to be performed during signature generation.\n\nlibcrux-ml-dsa did not perform this check correctly during signature verification, accepting signatures with signer response norm above the allowed maximum value. The check is correctly performed during signing.\n\n## Impact\nApplications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.\n\n## Mitigation\nStarting from version `0.0.8`, signature verification uses the correct value for $\\gamma_1$ in the signer response norm check.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/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-347"],"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/1347","tags":["web"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0077.html","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-cp57-fq8g-qh6v"},{"url":"https://github.com/cryspen/libcrux","tags":["package"]},{"url":"https://crates.io/crates/libcrux-ml-dsa","tags":["package"]}],"sources":{"ghsa":[{"id":"GHSA-cp57-fq8g-qh6v","title":"libcrux has an Incorrect Check of Signer Response Norm During Verification","description":"The ML-DSA verification algorithm as specified in [FIPS 204, subsection 6.3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#subsection.6.3) requires verifiers to check that the infinity norm of the deserialized signer response $z$ does not exceed $\\gamma_1 - \\beta$ (line 13 of Algorithm 8). The same check is required to be performed during signature generation.\n\nlibcrux-ml-dsa did not perform this check correctly during signature verification, accepting signatures with signer response norm above the allowed maximum value. The check is correctly performed during signing.\n\n## Impact\nApplications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.\n\n## Mitigation\nStarting from version `0.0.8`, signature verification uses the correct value for $\\gamma_1$ in the signer response norm check.","status":"published","published":"2026-03-26T18:00:28Z","modified":"2026-03-26T18:00:30Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:39:42.712607Z"}],"osv":[{"id":"GHSA-cp57-fq8g-qh6v","title":"libcrux has an Incorrect Check of Signer Response Norm During Verification","description":"The ML-DSA verification algorithm as specified in [FIPS 204, subsection 6.3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#subsection.6.3) requires verifiers to check that the infinity norm of the deserialized signer response $z$ does not exceed $\\gamma_1 - \\beta$ (line 13 of Algorithm 8). The same check is required to be performed during signature generation.\n\nlibcrux-ml-dsa did not perform this check correctly during signature verification, accepting signatures with signer response norm above the allowed maximum value. The check is correctly performed during signing.\n\n## Impact\nApplications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.\n\n## Mitigation\nStarting from version `0.0.8`, signature verification uses the correct value for $\\gamma_1$ in the signer response norm check.","status":"published","published":"2026-03-26T18:00:28Z","modified":"2026-03-27T06:11:21.668298Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:46:45.28161Z"},{"id":"RUSTSEC-2026-0077","title":"Incorrect Check of Signer Response Norm During Verification","description":"The ML-DSA verification algorithm as specified in [FIPS 204,\nsubsection\n6.3](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#subsection.6.3)\nrequires verifiers to check that the infinity norm of the deserialized\nsigner response $z$ does not exceed $\\gamma_1 - \\beta$ (line 13 of\nAlgorithm 8).\nThe same check is required to be performed during signature generation.\n\nlibcrux-ml-dsa did not perform this check correctly during signature\nverification, accepting signatures with signer response norm above the\nallowed maximum value.  The check is correctly performed during\nsigning.\n\n## Impact\nApplications using libcrux-ml-dsa for signature verification would\nhave accepted signatures that would be rejected by a conforming\nimplementation.\n\n## Mitigation\nStarting from version `0.0.8`, signature verification uses the correct\nvalue for $\\gamma_1$ in the signer response norm check.","status":"published","published":"2026-03-04T12:00:00Z","modified":"2026-03-27T05:55:06Z","updated_at":"2026-11-02T15:53:40.430679Z"}]}}