CVE-2026-24850
Unknown Unknown - Not Provided
Signature Verification Bypass in RustCrypto ml-dsa Crate

Publication date: 2026-01-28

Last updated on: 2026-01-28

Assigner: GitHub, Inc.

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.
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Meta Information
Published
2026-01-28
Last Modified
2026-01-28
Generated
2026-06-16
AI Q&A
2026-01-29
EPSS Evaluated
2026-06-15
NVD
CVE-2026-24850
EUVD
EUVD-2026-4910
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
unknown_vendor ml-dsa From 0.0.4 (inc) to 0.1.0-rc.4 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-347 The product does not verify, or incorrectly verifies, the cryptographic signature for data.
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Executive Summary

The vulnerability is in the ML-DSA Rust crate's signature verification implementation. It incorrectly accepts signatures that have repeated (duplicate) hint indices within each polynomial, which violates the ML-DSA specification requiring strictly increasing hint indices. This happened because a code change replaced a strict less-than comparison (<) with a less-than-or-equal-to (<=) comparison, allowing duplicates. This is a regression bug fixed in version 0.1.0-rc.4.

Impact Analysis

This vulnerability can impact you by allowing invalid signatures with duplicate hint indices to be accepted as valid. This could undermine the integrity of digital signatures verified using the affected ML-DSA crate, potentially allowing attackers to forge or manipulate signatures without detection.

Mitigation Strategies

Update the ML-DSA crate to version 0.1.0-rc.4 or later, as this version fixes the issue with signature verification accepting duplicate hint indices. Avoid using versions from 0.0.4 up to but not including 0.1.0-rc.4.

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