CVE-2026-3549

EUVD-2026-13168
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 7%
Affected Products (NVD)
VendorProductVersion
wolfsslwolfssl
𝑥
< 5.9.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
wolfssl
bookworm
no-dsa
bullseye
postponed
forky
5.9.1-0.1
fixed
sid
5.9.1-0.1
fixed
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
wolfssl
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
needs-triage
resolute
needs-triage
xenial
needs-triage