CVE-2026-3549

CRITICAL

9.8

Description

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.

CVE Details

CVSS v3.1 Score9.8

SeverityCRITICAL

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published3/19/2026

Last Modified3/26/2026

Sourcenvd

Honeypot Sightings0

Affected Products

wolfssl:wolfssl

Weaknesses (CWE)

CWE-122

References

https://github.com/wolfSSL/wolfssl/pull/9817(facts@wolfssl.com)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.