CVE-2026-23558
Xen Hypervisor Race Condition in Grant Table Version Change
Publication date: 2026-05-19
Last updated on: 2026-05-19
Assigner: Xen Project
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| xen | xen | From 4.0.0 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-362 | The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
CVE-2026-23558 is a race condition vulnerability in the Xen hypervisor that can lead to privilege escalation, information leaks, or Denial of Service (DoS) affecting the entire host.
Such security issues could potentially impact compliance with standards and regulations like GDPR or HIPAA, which require protection of sensitive data and system integrity.
However, the provided information does not explicitly discuss or analyze the direct impact of this vulnerability on compliance with these or other common standards and regulations.
Can you explain this vulnerability to me?
CVE-2026-23558 is a race condition vulnerability in the Xen hypervisor's grant table version 2 implementation. It occurs when an HVM or PVH guest switches from grant table version 2 to version 1 while simultaneously mapping status pages using XENMEM_add_to_physmap. This race condition can cause some status pages to be freed while their mappings are still inserted into the guest's secondary page tables.
How can this vulnerability impact me? :
This vulnerability can lead to privilege escalation, information leaks, or Denial of Service (DoS) that can affect the entire host system running the Xen hypervisor.
What immediate steps should I take to mitigate this vulnerability?
To mitigate the CVE-2026-23558 vulnerability, you should set the hypervisor command line option "gnttab=max-ver:1" or the guest configuration option "max_grant_version=1" for HVM and PVH guests.
Additionally, applying the available patches for Xen versions 4.19.x, 4.18.x, and 4.17.x will resolve the issue.