CVE-2026-31414

Name	CVE-2026-31414
Description	In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: use expect->helper Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to the skb.
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-4561-1, DSA-6238-1, DSA-6243-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	vulnerable
	bullseye (security)	5.10.251-3	vulnerable
	bookworm	6.1.159-1	vulnerable
	bookworm (security)	6.1.170-1	fixed
	trixie	6.12.73-1	vulnerable
	trixie (security)	6.12.85-1	fixed
	forky	6.19.14-1	fixed
	sid	7.0.3-1	fixed
linux-6.1 (PTS)	bullseye (security)	6.1.170-1~deb11u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bookworm	6.1.170-1	DSA-6243-1
linux	source	trixie	6.12.85-1	DSA-6238-1
linux	source	(unstable)	6.19.12-1
linux-6.1	source	bullseye	6.1.170-1~deb11u1	DLA-4561-1

https://git.kernel.org/linus/f01794106042ee27e54af6fdf5b319a2fe3df94d (7.0-rc6)