Race condition in Xen - CVE-2026-23558
Published: April 28, 2026
Vulnerability identifier: #VU128376
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23558
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Xen
Xen
Software vendor:
Xen Project
Xen Project
Description
The vulnerability allows a remote user to escalate privileges, disclose sensitive information, or cause a denial of service.
The vulnerability exists due to a race condition in status page mapping via XENMEM_add_to_physmap when changing the grant table version from v2 to v1 in parallel with mapping status pages. A remote user can trigger concurrent grant table version changes and status page mappings to escalate privileges, disclose sensitive information, or cause a denial of service.
Only x86 HVM and PVH guests permitted to use grant table version 2 interfaces can leverage this vulnerability.
Remediation
Install security update from vendor's website.