CVE-2026-0665

Publication date 18 February 2026

Last updated 27 February 2026

Ubuntu priority

Cvss 3 Severity Score

Description

An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
qemu	25.10 questing	Vulnerable
	25.04 plucky	Ignored end of life, was needed
	24.04 LTS noble	Vulnerable
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

mdeslaur

introduced in 8.0.0 via: https://gitlab.com/qemu-project/qemu/-/commit/aa98ee38a5e77d1e40987c694abd0c5bc5d6c811

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
qemu	Upstream: c7504ba

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Changed
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H