CVE-2026-31738

Name	CVE-2026-31738
Description	In the Linux kernel, the following vulnerability has been resolved: vxlan: validate ND option lengths in vxlan_na_create vxlan_na_create() walks ND options according to option-provided lengths. A malformed option can make the parser advance beyond the computed option span or use a too-short source LLADDR option payload. Validate option lengths against the remaining NS option area before advancing, and only read source LLADDR when the option is large enough for an Ethernet address.
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-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)	5.10.251-5	vulnerable
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.172-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.88-1	fixed
	forky, sid	7.0.7-1	fixed
linux-6.1 (PTS)	bullseye (security)	6.1.172-1~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
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/afa9a05e6c4971bd5586f1b304e14d61fb3d9385 (7.0-rc7)