CVE-2025-48946
Published: 30 May 2025
Summary
CVE-2025-48946 is a low-severity Use of a Broken or Risky Cryptographic Algorithm (CWE-327) vulnerability in Openquantumsafe Liboqs. Its CVSS base score is 3.7 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Reduce Key Space (T1600.001); ranked at the 34.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as Other Platforms; in the Protocol-Specific Risks risk domain.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-16528
Vulnerability details
liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. liboqs prior to version 0.13.0 supports the HQC algorithm, an algorithm with a theoretical design flaw which leads to large numbers of malformed ciphertexts sharing the same…
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implicit rejection value. Currently, no concrete attack on the algorithm is known. However, prospective users of HQC must take extra care when using the algorithm in protocols involving key derivation. In particular, HQC does not provide the same security guarantees as Kyber or ML-KEM. There is currently no patch for the HQC flaw available in liboqs, so HQC is disabled by default in liboqs starting from version 0.13.0. OQS will update its implementation after the HQC team releases an updated algorithm specification.
- CWE(s)
AI Security AnalysisAI
- AI Category
- Other Platforms
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: ml
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The theoretical design flaw in the HQC algorithm causes many malformed ciphertexts to share the same implicit rejection value, potentially enabling attacks that reduce the effective key space and weaken encryption security, especially in key derivation protocols.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Contacts with security groups provide timely information on broken or risky cryptographic algorithms, reducing the likelihood of their selection and use.
Ongoing education and sharing of recommended practices helps organizations identify and migrate away from broken or risky cryptographic algorithms.
Cross-organization threat feeds commonly include advances in cryptanalysis and active exploits against weak or broken algorithms, allowing organizations to deprecate them proactively.
Capital planning and funding allow selection and ongoing support of strong cryptographic algorithms rather than weak or broken ones.
Risk updates surface newly-broken or risky cryptographic algorithms as threat intelligence and computing advances evolve, enabling timely replacement.
Scanners flag use of broken or weak cryptographic algorithms via known-vulnerability databases.
Enforces approved cryptographic algorithms for each use case, blocking use of broken or risky algorithms.
Flaw remediation replaces broken or risky cryptographic algorithms once safer implementations are released by vendors.