Vulnerability in Open-Quantum-Safe Liboqs
CVE-2026-47738
liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Prior to 0.16.0, OQS_KEM_encaps_derand can dereference an uninitialized encaps_derand function pointer when called on NTRU-HPS-2048-509, NTRU-HPS-2048-677, NTRU-HPS-4096-821, NTRU-HPS-4096-1229, NTRU-HRSS-701, or NTRU-HRSS-1373. The affected NTRU constructors omit the OQS_KEM.encaps_derand member because those schemes do not support derandomized encapsulation, OQS_KEM objects are allocated without zero initialization, and the wrapper in src/kem/kem.c checks only that the OQS_KEM pointer is non-null before calling through the residual heap value. An application is affected only if it instantiates one of those six NTRU KEMs and invokes OQS_KEM_encaps_derand on it. The supported impact is a calling-process crash and denial of service. This issue is fixed in version 0.16.0.
Published .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Open-Quantum-Safe Liboqs — versions < 0.16.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-47738?
- CVE-2026-47738 is a medium-severity vulnerability in Open-Quantum-Safe Liboqs, classified under Access of Uninitialized Pointer. CVSS score: 5.3/10. Published 2026-11-06.
- How severe is CVE-2026-47738?
- Medium severity. CVSS v3 base score is 5.3 out of 10.