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Fencer Vulns
medium 5.3

CVE-2026-46344 json

liboqs: Heap-buffer-overflow in XMSS verification path via OID-controlled parameter mismatch (xmss_commons.c:194)

published 2026-05-29 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-33413

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Prior to 0.16.0, an out-of-bounds read has been identified in the XMSS and XMSS^MT stateful signature verification code. When the verification function is called with a correctly-sized signature buffer for the declared algorithm but a public key whose OID bytes (pk[0..3]) reference a different XMSS parameter set with a larger sig_bytes, the implementation re-parses the OID from the public key inside xmss_sign_open / xmssmt_sign_open and uses the resulting (larger) sig_bytes to index the caller-supplied signature buffer. As with CVE-2026-44518, the out-of-bounds bytes are consumed only as input to an internal hash computation and are not returned to the caller, so no oracle exists to leak their contents to an attacker. The primary observable effect is a possible crash (denial of service) of the verifying process if the read crosses into an unmapped memory page. This vulnerability is fixed in 0.16.0.

Patch / fix

  • openquantumsafe liboqs 0.16.0
  • liboqs SLES for SAP applications 16.0, SLES 16.0 0.16.0-160000.1.1
  • oqs-provider SLES for SAP applications 16.0, SLES 16.0 0.11.0.32-160000.1.1
  • oqs-provider SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 0.11.0.32-150600.3.9.1
  • liboqs SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 0.16.0-150600.3.6.1

suse advisories SUSE-SU-2026:23313-1SUSE-SU-2026:3420-1

  • liboqs openSUSE Leap 16.0 0.16.0-160000.1.1
  • oqs-provider openSUSE Leap 16.0 0.11.0.32-160000.1.1
  • liboqs openSUSE Tumbleweed 0.16.0-2.1

opensuse advisories openSUSE-SU-2026:21634-1openSUSE-SU-2026:11365-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46344 updated cvss 5.3

liboqs: liboqs: Denial of Service due to out-of-bounds read in XMSS/XMSS^MT signature verification

  • Red Hat Enterprise Linux 10 liboqs
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

  • open-quantum-safe liboqs

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.