Race condition in Xen - CVE-2026-42487
Published: June 9, 2026
Vulnerability identifier: #VU134006
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-42487
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Xen Project
Affected software:
Xen
Xen
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper synchronization in the I/O port mapping list traversal logic when handling guest I/O port accesses. A remote user can modify I/O port mappings during traversal to cause a denial of service.
Only x86 systems are vulnerable. Exploitation requires control of an HVM guest device model running in a stub domain or de-privileged in Dom0.
How to mitigate CVE-2026-42487
Install security update from vendor's website.