{"id":"CVE-2026-44519","published":"2026-11-06T22:17:51.403","lastModified":"2026-11-10T21:19:30.350","description":"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.","cvssScore":5.1,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","cwes":["CWE-385"],"vendors":[],"products":[],"references":[{"url":"https://github.com/open-quantum-safe/liboqs/commit/d95fc734f5de9bdfc80c8c65d8166b30e9cff5cd","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/pull/2431","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/releases/tag/0.16.0","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/security/advisories/GHSA-5c97-hp95-vg56","tags":[]}],"exploitRefs":[{"url":"https://github.com/open-quantum-safe/liboqs/commit/d95fc734f5de9bdfc80c8c65d8166b30e9cff5cd","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/pull/2431","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/releases/tag/0.16.0","tags":[]},{"url":"https://github.com/open-quantum-safe/liboqs/security/advisories/GHSA-5c97-hp95-vg56","tags":[]}],"hasPoc":true,"ai":null}