Is CVE-2026-44519 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44519 being exploited in the wild.

How severe is CVE-2026-44519?

Medium severity, with a CVSS score of 5.1, published 6 November 2026.

Which products and versions are affected?

Open Quantum Safe Liboqs before 0.16.0.

Is there a fix for CVE-2026-44519?

Yes: fixed in 0.16.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-44519 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-44519?

Check whether you run Open Quantum Safe Liboqs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-44519: Open Quantum Safe liboqs FrodoKEM cache timing in ct_select

CVE-2026-44519 · Severity: medium · CVSS 5.1 · Published 2026-11-06

liboqs is a cryptographic library implementing post-quantum cryptography algorithms including FrodoKEM. When compiled with Clang 17 or later at certain optimization levels, the FrodoKEM decapsulation function contains a secret-dependent memory access pattern that leaks information about whether decryption succeeded or failed via CPU cache timing. A local attacker with repeated measurement access could potentially recover the private key through this timing side channel.

Technologies: Open Quantum Safe Liboqs. Vendors: Open Quantum Safe.

Quick answers

Is CVE-2026-44519 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44519 being exploited in the wild.
How severe is CVE-2026-44519?: Medium severity, with a CVSS score of 5.1, published 6 November 2026.
Which products and versions are affected?: Open Quantum Safe Liboqs before 0.16.0.
Is there a fix for CVE-2026-44519?: Yes: fixed in 0.16.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44519 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-44519?: Check whether you run Open Quantum Safe Liboqs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.16.0

Technical details

The ct_select function in src/kem/frodokem/external/util.c lacks a value barrier in the Fujisaki-Okamoto rejection sampling path, allowing Clang 17+ to emit a secret-dependent conditional load at optimization levels like -Os. This creates observable cache residency differences between successful and failed decapsulation paths, exploitable via cache-timing side-channel attacks. The issue is fixed by adding an OQS_MEM_BLACK_BOX optimization barrier to prevent compiler optimization that would expose the secret-dependent branch.

Affected products

Open Quantum Safe liboqs before 0.16.0

Timeline

2026-11-06: disclosed

References

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