CVE-2026-3549
March 19, 2026
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.
Affected Packages
https://github.com/wolfSSL/wolfssl.git (GITHUB):
Affected version(s) >=v0.5 <v5.9.0-stableFix Suggestion:
Update to version v5.9.0-stableRelated Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
LOW
CVSS v3
Base Score:
9.9
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
HIGH
Weakness Type (CWE)
Heap-based Buffer Overflow
EPSS
Base Score:
0.07
