Buffer overflow in Wofssl Wolfssl
CVE-2026-3549
Heap Overflow in TLS 1.3 ECH parsing. An integer underflow existed in ECH extension parsing logic when calculating a buffer length, which resulted in writing beyond the bounds of an allocated buffer. Note that in wolfSSL, ECH is off by default, and the ECH standard is still evolving.
Vulnerability class: Buffer Overflow
EPSS: 0.005 (39.2th 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
- Wofssl Wolfssl — versions 0
- Wolfssl
Weakness classification (CWE)
References
- facts@wolfssl.com (Patch, Issue Tracking)
Frequently asked questions
- What is CVE-2026-3549?
- CVE-2026-3549 is a critical-severity vulnerability in Wofssl Wolfssl, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-03-19.
- How severe is CVE-2026-3549?
- Critical severity. CVSS v3 base score is 9.8 out of 10.