CVE-2026-43190

Name	CVE-2026-43190
Description	In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_tcpmss: check remaining length before reading optlen Quoting reporter: In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads op[i+1] directly without validating the remaining option length. If the last byte of the option field is not EOL/NOP (0/1), the code attempts to index op[i+1]. In the case where i + 1 == optlen, this causes an out-of-bounds read, accessing memory past the optlen boundary (either reading beyond the stack buffer _opt or the following payload).
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)

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

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

Package	Type	Release	Fixed Version
linux	source	bookworm	6.1.170-1
linux	source	trixie	6.12.85-1
linux	source	(unstable)	6.19.6-1

https://git.kernel.org/linus/735ee8582da3d239eb0c7a53adca61b79fb228b3 (7.0-rc1)