Information disclosure in Open-Quantum-Safe Liboqs

CVE-2025-52473

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Multiple secret-dependent branches have been identified in the reference implementation of the HQC key encapsulation mechanism when it is compiled with Clang for optimization levels above -O0 (-O1, -O2, etc). A proof-of-concept local attack exploits this secret-dependent information to recover the entire secret key. This vulnerability is fixed in 0.14.0.

Vulnerability class: Information Disclosure

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (13.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 13.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-52473: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-52473?
CVE-2025-52473 is a medium-severity vulnerability in Open-Quantum-Safe Liboqs, classified under Information Disclosure. CVSS score: 5.9/10. Published 2025-07-10.
How severe is CVE-2025-52473?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2025-52473 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.