CVE-2026-0665

Publication date 18 February 2026

Last updated 4 March 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.5 · Medium

Score breakdown

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

Package Ubuntu Release Status
qemu 25.10 questing
Fixed 1:10.1.0+ds-5ubuntu2.4
25.04 plucky Ignored end of life, was needed
24.04 LTS noble
Fixed 1:8.2.2+ds-0ubuntu1.13
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

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

References

Related Ubuntu Security Notices (USN)

Other references