CVE-2026-46344: Open Quantum Safe liboqs out-of-bounds read in XMSS verification

CVE-2026-46344 · Severity: medium · CVSS 5.3 · Published 2026-05-29

liboqs is a software library used to implement next-generation 'post-quantum' cryptography. A flaw in how it verifies digital signatures could allow an attacker to provide a specially crafted public key that causes the software to crash. This results in a denial-of-service, potentially disrupting systems that rely on this library for secure communications or firmware updates.

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

Quick answers

Is CVE-2026-46344 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-46344 being exploited in the wild.
How severe is CVE-2026-46344?
Medium severity, with a CVSS score of 5.3, published 29 May 2026.
Which products and versions are affected?
Open Quantum Safe Liboqs < 0.16.0.
Is there a fix for CVE-2026-46344?
A patch was published on 2026-05-29: Fix included in version 0.16.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-46344 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-46344?
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.

Technical details

An out-of-bounds (OOB) read exists in the XMSS and XMSS^MT stateful signature verification implementation within liboqs. The vulnerability occurs because the verification wrappers fail to validate that the Object Identifier (OID) encoded in the first four bytes of a public key matches the expected algorithm's OID. When a mismatch occurs where the provided OID specifies a larger signature size than the actual buffer, the library uses the larger size to index the signature buffer during internal hash computations. This can result in a heap-based OOB read. While the data is not leaked to the caller, the read can cause a process crash if it accesses unmapped memory. The issue was fixed in version 0.16.0 by adding an OID consistency check at the API boundary.

Affected products

  • Open Quantum Safe (OQS) liboqs < 0.16.0

Timeline

  • 2026-05-15: advisory: GitHub Advisory GHSA-2wxh-55qf-c7wg published
  • 2026-05-29: disclosed: CVE-2026-46344 published to NVD
  • 2026-05-29: patched: Fix included in version 0.16.0

References

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