Medium 5.3Published Jan 27, 2026

CVE-2026-24850ML-DSA Signature Verification Accepts Signatures with Repeated Hint Indices

Updated under an hour ago (Oct 27, 2026, 6:40 AM ET)

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Exploited in the last 30 days

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: 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-347
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Jan 28, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

RustCrypto signatures rustcrypto:signatures (from the name)	from 0.0.4, < 0.1.0-rc.4	CNA record

References

References

https://github.com/RustCrypto/signatures/security/advisories/GHSA-5x2r-hc65-25f9	x-refsource-confirm
https://github.com/RustCrypto/signatures/issues/894	x-refsource-misc
https://github.com/RustCrypto/signatures/pull/895	x-refsource-misc
https://github.com/RustCrypto/signatures/commit/400961412be2e2ab787942cf30e0a9b66b37a54a	x-refsource-misc
https://github.com/RustCrypto/signatures/commit/b01c3b73dd08d0094e089aa234f78b6089ec1f38	x-refsource-misc
https://csrc.nist.gov/pubs/fips/204/final	x-refsource-misc
https://datatracker.ietf.org/doc/html/rfc9881	x-refsource-misc
https://github.com/C2SP/wycheproof	x-refsource-misc
https://github.com/C2SP/wycheproof/blob/master/testvectors_v1/mldsa_44_verify_test.json	x-refsource-misc
https://github.com/C2SP/wycheproof/blob/master/testvectors_v1/mldsa_65_verify_test.json	x-refsource-misc
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.