CVE-2026-3547

HIGH

wolfSSL: out-of-bounds read (DoS) in ALPN parsing due to incomplete validation

Title source: cna

Description

Out-of-bounds read in ALPN parsing due to incomplete validation. wolfSSL 5.8.4 and earlier contained an out-of-bounds read in ALPN handling when built with ALPN enabled (HAVE_ALPN / --enable-alpn). A crafted ALPN protocol list could trigger an out-of-bounds read, leading to a potential process crash (denial of service). Note that ALPN is disabled by default, but is enabled for these 3rd party compatibility features: enable-apachehttpd, enable-bind, enable-curl, enable-haproxy, enable-hitch, enable-lighty, enable-jni, enable-nginx, enable-quic.

References (1)

[Patch] https://github.com/wolfSSL/wolfssl/pull/9859

Scores

CVSS v3 7.5

EPSS 0.0005

EPSS Percentile 15.6%

Attack Vector NETWORK

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

Details

CWE

CWE-125

Status published

Products (2)

wolfSSL/wolfSSL < 5.9.0

wolfssl/wolfssl < 5.9.0

Published Mar 19, 2026

Tracked Since Mar 20, 2026