CVE-2026-24850
The current implementation uses a non-strict monotonic check (`<=` instead of `<`), allowing duplicate indices.
Does this matter?
Lower severity and a low EPSS score (0.31%). Track it; it rarely justifies an emergency change on its own.
Description
The ML-DSA crate is a Rust implementation of the Module-Lattice-Based Digital Signature Standard (ML-DSA). Starting in version 0.0.4 and prior to version 0.1.0-rc.4, the ML-DSA signature verification implementation in the RustCrypto `ml-dsa` crate incorrectly accepts signatures with repeated (duplicate) hint indices. According to the ML-DSA specification (FIPS 204 / RFC 9881), hint indices within each polynomial must be **strictly increasing**. The current implementation uses a non-strict monotonic check (`<=` instead of `<`), allowing duplicate indices. This is a regression bug. The original implementation was correct, but a commit in version 0.0.4 inadvertently changed the strict `<` comparison to `<=`, introducing the vulnerability. Version 0.1.0-rc.4 fixes the issue.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.31% probability · 24th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Source
- security-advisories@github.com
References
- https://csrc.nist.gov/pubs/fips/204/final
- https://datatracker.ietf.org/doc/html/rfc9881
- https://github.com/C2SP/wycheproof
- https://github.com/C2SP/wycheproof/blob/master/testvectors_v1/mldsa_44_verify_test.json
- https://github.com/C2SP/wycheproof/blob/master/testvectors_v1/mldsa_65_verify_test.json
- https://github.com/C2SP/wycheproof/blob/master/testvectors_v1/mldsa_87_verify_test.json
- https://github.com/RustCrypto/signatures/commit/400961412be2e2ab787942cf30e0a9b66b37a54a
- https://github.com/RustCrypto/signatures/commit/b01c3b73dd08d0094e089aa234f78b6089ec1f38
- https://github.com/RustCrypto/signatures/issues/894
- https://github.com/RustCrypto/signatures/pull/895
- https://github.com/RustCrypto/signatures/security/advisories/GHSA-5x2r-hc65-25f9
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.