CVE-2026-5460 PUBLISHED

Heap Use-After-Free in PQC Hybrid KeyShare Error Cleanup in wolfSSL TLS 1.3

Assigner: wolfSSL
Reserved: 02.04.2026 Published: 09.04.2026 Updated: 10.04.2026

A heap use-after-free exists in wolfSSL's TLS 1.3 post-quantum cryptography (PQC) hybrid KeyShare processing. In the error handling path of TLSX_KeyShare_ProcessPqcHybridClient() in src/tls.c, the inner function TLSX_KeyShare_ProcessPqcClient_ex() frees a KyberKey object upon encountering an error. The caller then invokes TLSX_KeyShare_FreeAll(), which attempts to call ForceZero() on the already-freed KyberKey, resulting in writes of zero bytes over freed heap memory.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
CVSS Score: 6.3

Product Status

Vendor wolfSSL
Product wolfSSL
Versions Default: unaffected
  • affected from 0 to 5.9.1 (excl.)

Credits

  • Calvin Young (eWalker Consulting Inc.) finder
  • Enoch Chow (Isomorph Cyber) finder

References

Problem Types

  • CWE-416 Use After Free CWE