GHSA-cp57-fq8g-qh6v
libcrux has an Incorrect Check of Signer Response Norm During Verification
GHSA-cp57-fq8g-qh6v is a high vulnerability (CVSS 8.7) in libcrux-ml-dsa, published March 4, 2026. No source lists public exploit code. Fixed in libcrux-ml-dsa 0.0.8.
- Severity
- 8.7 HighCVSS 4.0, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
0.0.8libcrux-ml-dsa +1 more
Description
The ML-DSA verification algorithm as specified in FIPS 204, 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.
libcrux-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.
Impact
Applications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.
Mitigation
Starting from version 0.0.8, signature verification uses the correct value for $\gamma_1$ in the signer response norm check.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libcrux-ml-dsacrates.io | before 0.0.8 | 0.0.8 |
libcrux-ml-dsacrates.io | 0.0.0-0 up to 0.0.8 | 0.0.8 |
What each source reports
GitHub Advisories Score used
libcrux has an Incorrect Check of Signer Response Norm During Verification
The ML-DSA verification algorithm as specified in FIPS 204, 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.
libcrux-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.
Impact
Applications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.
Mitigation
Starting from version 0.0.8, signature verification uses the correct value for $\gamma_1$ in the signer response norm check.
- Record
GHSA-cp57-fq8g-qh6v- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-347
- Updated
- 2026-11-02
OSV
libcrux has an Incorrect Check of Signer Response Norm During Verification
The ML-DSA verification algorithm as specified in FIPS 204, 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.
libcrux-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.
Impact
Applications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.
Mitigation
Starting from version 0.0.8, signature verification uses the correct value for $\gamma_1$ in the signer response norm check.
- Record
GHSA-cp57-fq8g-qh6v- CVSS 4.0
- 8.7 High
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 - Weakness
- CWE-347
- Updated
- 2026-11-02
OSVRUSTSEC-2026-0077No score
Incorrect Check of Signer Response Norm During Verification
The ML-DSA verification algorithm as specified in FIPS 204, 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.
libcrux-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.
Impact
Applications using libcrux-ml-dsa for signature verification would have accepted signatures that would be rejected by a conforming implementation.
Mitigation
Starting from version 0.0.8, signature verification uses the correct
value for $\gamma_1$ in the signer response norm check.
- Record
RUSTSEC-2026-0077- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.