CVSS 3.1
5.1 mediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCVE-2026-44519
Medium (5.1) in open-quantum-safe liboqs. EPSS 0.1% estimated probability of exploitation activity in the next 30 days.
On this page
liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Prior to 0.16.0, the ct_select function in src/kem/frodokem/external/util.c for the FrodoKEM-640, FrodoKEM-976, and FrodoKEM-1344 AES and SHAKE reference variants lacks a value barrier in the Fujisaki-Okamoto implicit-rejection path. When compiled with Clang 17 or later at an affected optimization level such as -Os, the compiler can emit a secret-dependent conditional load, causing the real and rejection secret paths to leave distinguishable cache residency after successful and failed decapsulation. A local attacker able to perform repeated cache-timing measurements may use this oracle as part of a private-key recovery attack. Default -O3 builds vectorize both source loads and do not exhibit the reported behavior, and the advisory does not report the same generated memory-access pattern in NTRU, NTRU-Prime, BIKE, HQC, Classic McEliece, Kyber, or the already-barriered ML-KEM implementation. This issue is fixed in version 0.16.0.
Severity
- EPSS
- 0.1% estimated probability of exploitation activity in the next 30 days; 2nd percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-385 Covert Timing Channel
- Published
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Explain CVE-2026-44519 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-44519?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-44519?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-44519 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| open-quantum-safe liboqs | < 0.16.0 |
Attack patterns (CAPEC)
- CAPEC-462 Cross-Domain Search Timing Severity: Medium
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.