CVE-2025-27465

Name	CVE-2025-27465
Description	Certain instructions need intercepting and emulating by Xen. In some cases Xen emulates the instruction by replaying it, using an executable stub. Some instructions may raise an exception, which is supposed to be handled gracefully. Certain replayed instructions have additional logic to set up and recover the changes to the arithmetic flags. For replayed instructions where the flags recovery logic is used, the metadata for exception handling was incorrect, preventing Xen from handling the the exception gracefully, treating it as fatal instead.
Source	CVE (at NVD; CERT, 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)	bullseye	4.14.6-1	vulnerable
	bullseye (security)	4.14.5+94-ge49571868d-1	vulnerable
	bookworm	4.17.5+23-ga4e5191dc0-1+deb12u1	vulnerable
	bookworm (security)	4.17.5+23-ga4e5191dc0-1	vulnerable
	forky, sid, trixie	4.20.0+68-g35cb38b222-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
xen	source	bullseye	(unfixed)	end-of-life
xen	source	(unstable)	(unfixed)

[bullseye] - xen <end-of-life> (EOLed in Bullseye)
https://xenbits.xen.org/xsa/advisory-470.html