CVE-2026-43020

Name	CVE-2026-43020
Description	In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate LTK enc_size on load Load Long Term Keys stores the user-provided enc_size and later uses it to size fixed-size stack operations when replying to LE LTK requests. An enc_size larger than the 16-byte key buffer can therefore overflow the reply stack buffer. Reject oversized enc_size values while validating the management LTK record so invalid keys never reach the stored key state.
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/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15 (7.0-rc7)