CVE-2026-44519— liboqs: Missing value barrier in FO implicit rejection path (FrodoKEM, NTRU, and others)

Quick assessment

Affected

open-quantum-safe liboqs

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

liboqs 是一个用 C 语言编写的密码学库，提供了后量子密码算法的实现。在 0.16.0 版本之前，FrodoKEM-640、FrodoKEM-976 和 FrodoKEM-1344 的 AES 与 SHAKE 参考变体中，位于的函数在 Fujisaki-Okamoto 隐式拒绝路径中缺少值屏障（value barrier）。当使用 Clang 17 或更高版本在受影响优化级别（例如）下编译时，编译器可能生成依赖密钥的条件加载指令，导致成功解封装与失败解封装后，真实密钥路径与拒绝密钥路径在缓存驻留状态上产

CVSS 5.1 · Medium Updated Nov 07, 2026

Possible ATT&CK Techniques 1 AI

T1055 · Process Injection

Get alerts for future matching vulnerabilities Log in to subscribe

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!

View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title

liboqs: Missing value barrier in FO implicit rejection path (FrodoKEM, NTRU, and others)

Source: CVE Program / CVE List V5

Vulnerability 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.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

隐蔽时间通道

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
open-quantum-safe	liboqs	< 0.16.0	-

II. Public POCs for CVE-2026-44519

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-44519

请登录查看更多情报信息。

Other References for CVE-2026-44519 (4)

https://github.com/open-quantum-safe/liboqs/pull/2431 x_refsource_MISC
https://github.com/open-quantum-safe/liboqs/releases/tag/0.16.0 x_refsource_MISC
https://github.com/open-quantum-safe/liboqs/security/advisories/GHSA-5c97-hp95-vg56 x_refsource_CONFIRM
https://github.com/open-quantum-safe/liboqs/commit/d95fc734f5de9bdfc80c8c65d8166b30e9cff5cd x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-44519

Same Patch Batch · open-quantum-safe · 2026-11-06 · 3 CVEs total

CVE-2026-104254	5.3 MEDIUM	liboqs: Heap out-of-bounds read in LMS/HSS signature verification via unvalidated signatur
CVE-2026-47738	5.3 MEDIUM	liboqs: Uninitialized function-pointer dereference in OQS_KEM_encaps_derand for NTRU KEMs

IV. Related Vulnerabilities

Same product: liboqs

Same vendor: open-quantum-safe

Same weakness: CWE-385