CVE-2026-25075

Name	CVE-2026-25075
Description	strongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4512-1, DSA-6176-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
strongswan (PTS)	bullseye	5.9.1-1+deb11u4	vulnerable
	bullseye (security)	5.9.1-1+deb11u6	fixed
	bookworm	5.9.8-5+deb12u2	vulnerable
	bookworm (security)	5.9.8-5+deb12u3	fixed
	trixie	6.0.1-6+deb13u2	vulnerable
	trixie (security)	6.0.1-6+deb13u4	fixed
	forky, sid	6.0.5-1	fixed

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

Package	Type	Release	Fixed Version	Origin
strongswan	source	bullseye	5.9.1-1+deb11u6	DLA-4512-1
strongswan	source	bookworm	5.9.8-5+deb12u3	DSA-6176-1
strongswan	source	trixie	6.0.1-6+deb13u4	DSA-6176-1
strongswan	source	(unstable)	6.0.5-1

Notes

https://www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).html
Patch: https://download.strongswan.org/security/CVE-2026-25075/