CVE-2026-31637

Name	CVE-2026-31637
Description	In the Linux kernel, the following vulnerability has been resolved: rxrpc: reject undecryptable rxkad response tickets rxkad_decrypt_ticket() decrypts the RXKAD response ticket and then parses the buffer as plaintext without checking whether crypto_skcipher_decrypt() succeeded. A malformed RESPONSE can therefore use a non-block-aligned ticket length, make the decrypt operation fail, and still drive the ticket parser with attacker-controlled bytes. Check the decrypt result and abort the connection with RXKADBADTICKET when ticket decryption fails.
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)	5.10.251-1	vulnerable
	bookworm	6.1.159-1	vulnerable
	bookworm (security)	6.1.164-1	vulnerable
	trixie	6.12.73-1	vulnerable
	trixie (security)	6.12.74-2	vulnerable
	forky	6.19.13-1	fixed
	sid	6.19.14-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	(unstable)	6.19.13-1

https://git.kernel.org/linus/fe4447cd95623b1cfacc15f280aab73a6d7340b2 (7.0)