CVE-2026-23558 — HIGH (7.8)

Vulnerability Description

The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.

CVSS Score

7.8

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Xen	Xen	>= 4.0.0

Related Weaknesses (CWE)

CWE-362

References

https://xenbits.xenproject.org/xsa/advisory-486.htmlMitigationPatchVendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/28/13Mailing ListMitigationPatch
http://xenbits.xen.org/xsa/advisory-486.htmlMitigationPatchVendor Advisory

FAQ

What is CVE-2026-23558?

CVE-2026-23558 is a vulnerability with a CVSS score of 7.8 (HIGH). The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mappi...

How severe is CVE-2026-23558?

CVE-2026-23558 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-23558?

Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen.