CVE-2026-23558
7.8
HIGH
CVSS 3.1
EPSS 0.01%
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.
How to fix CVE-2026-23558
To remediate CVE-2026-23558, upgrade the affected package to a fixed version below.
- —upgrade to 4.18.5-r7 or later
- —no fix listed
Is CVE-2026-23558 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 4.18.5-r7
- from 0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.8 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |