CVE-2026-3547

NameCVE-2026-3547
DescriptionOut-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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
wolfssl (PTS)bullseye4.6.0+p1-0+deb11u2vulnerable
bookworm5.5.4-2+deb12u2vulnerable
trixie5.7.2-0.1+deb13u1vulnerable
forky5.8.4-1vulnerable
sid5.9.0-0.1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
wolfsslsource(unstable)5.9.0-0.1

Notes

https://github.com/wolfSSL/wolfssl/pull/9859
https://github.com/wolfSSL/wolfssl/pull/9860
Fixed by: https://github.com/wolfSSL/wolfssl/commit/9d3cc6e30c778b124002cc45b7974d718b6649fd (v5.9.0-stable)

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