High severity · published May 19, 2026
CVE-2026-23558
grant table v2 race in status page mapping
7.8
CVSS
0.1%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XE
Xen · Xen
4.0.0 and later · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-23558
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-23558
Mitigation
https://xenbits.xenproject.org/xsa/advisory-486.html
Mailing List
http://www.openwall.com/lists/oss-security/2026/04/28/13
Mitigation
http://xenbits.xen.org/xsa/advisory-486.html
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