CVE-2026-64380

Name	CVE-2026-64380
Description	In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.
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-4717-1, DLA-4720-1, DLA-4723-1, DLA-4724-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.180-1	fixed
	trixie	6.12.94-1	vulnerable
	trixie (security)	6.12.107-1	fixed
	forky	7.1.12-1	fixed
	sid	7.1.13-1	fixed
linux-6.12 (PTS)	bookworm (security)	6.12.101-1~deb12u1	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	bullseye	5.10.262-1	DLA-4717-1
linux	source	bookworm	6.1.180-1	DLA-4720-1
linux	source	trixie	6.12.96-1
linux	source	(unstable)	7.1.4-1
linux-6.1	source	bullseye	6.1.180-1~deb11u1	DLA-4723-1
linux-6.12	source	bookworm	6.12.100-1~deb12u1	DLA-4724-1

https://git.kernel.org/linus/7ad2bcf2441430bb2e918fb3ef9a90d775a6e422 (7.2-rc2)