Off-by-one in QEMU - CVE-2026-0665
Published: March 5, 2026
Vulnerability identifier: #VU123559
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:H/E:U/U:Clear
CVE-ID: CVE-2026-0665
CWE-ID: CWE-193
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: QEMU
Affected software:
QEMU
QEMU
Detailed vulnerability description
The vulnerability allows a malicious guest to perform a denial of service attack.
The vulnerability exists due to an off-by-one error within the KVM Xen guest support in hw/i386/kvm/xen_evtchn.c. A malicious guest can trigger an off-by-one error and perform a denial of service attack.
How to mitigate CVE-2026-0665
Install updates from vendor's website.