What is CVE-2026-5264?

CVE-2026-5264 is a critical-severity vulnerability in Wolfssl, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-04-09.

How severe is CVE-2026-5264?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Wolfssl

CVE-2026-5264

Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (33.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Wolfssl — versions 0

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

facts@wolfssl.com (Patch, Issue Tracking)

Frequently asked questions

What is CVE-2026-5264?: CVE-2026-5264 is a critical-severity vulnerability in Wolfssl, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-04-09.
How severe is CVE-2026-5264?: Critical severity. CVSS v3 base score is 9.8 out of 10.