CVE-2026-79608

Name	CVE-2026-79608
Description	The workaround for XSA-433 (Zenbleed, CVE-2023-20593) was later re-worked to better integrate with other manipulations of the same MSR. In this rework an inverted conditional was introduced, resulting in the workaround to not be applied when needed and vice versa. For more details, see: http://xenbits.xen.org/xsa/advisory-433.html
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
xen (PTS)	bookworm	4.17.5+72-g01140da4e8-1	vulnerable
	bookworm (security)	4.17.7-0+deb12u1	vulnerable
	trixie (security), trixie	4.20.3+127-gc42374a105-0+deb13u1	vulnerable
	forky, sid	4.20.3+127-gc42374a105-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
xen	source	(unstable)	(unfixed)

https://xenbits.xen.org/xsa/advisory-515.html