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.

Score

CVSS 3.1 9.8 Critical

Status

Analyzed - facts@wolfssl.com

Published

2026-03-19

Last modified

2026-03-24

Weaknesses

CWE-122

Affected products

• Wolfssl (Wofssl)
• Wolfssl (Wolfssl)

References

• https://github.com/wolfSSL/wolfssl/pull/9817