Is CVE-2026-62436 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-62436 being exploited in the wild.

How severe is CVE-2026-62436?

Informational severity, with a CVSS score of 0, published 28 July 2026.

Is there a fix for CVE-2026-62436?

A patch was published on 2026-07-28. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-62436 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-62436?

Check whether you run Xen Project Xen at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-62436: Xen grant table race condition in version switching

CVE-2026-62436 · Severity: info · CVSS 0 · Published 2026-07-28

A vulnerability exists in the Xen hypervisor, which is software used to run multiple virtual machines on a single physical server. An attacker controlling a virtual machine could exploit a flaw in how the system manages memory sharing to gain full control over the host server. This could lead to the theft of data from other customers, a total system shutdown, or unauthorized access to the underlying infrastructure.

Technologies: Xen Project Xen. Vendors: Xen Project.

Quick answers

Is CVE-2026-62436 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-62436 being exploited in the wild.
How severe is CVE-2026-62436?: Informational severity, with a CVSS score of 0, published 28 July 2026.
Which products and versions are affected?: Xen Project Xen 4.0 and newer.
Is there a fix for CVE-2026-62436?: A patch was published on 2026-07-28. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-62436 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-62436?: Check whether you run Xen Project Xen at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A race condition exists in the Xen grant table implementation when switching between version 2 and version 1 (CVE-2026-62436). The vulnerability occurs because the code drops and re-acquires the grant table lock, incorrectly assuming that table properties (such as status frames) remain constant during the unlocked window. An unprivileged multi-vCPU x86 guest can exploit this timing window to trigger memory corruption or logic errors. This can result in guest-to-host privilege escalation, information disclosure, or a hypervisor crash. The issue affects all Xen versions from 4.0 onwards, specifically on x86 systems where grant table v2 is enabled.

Affected products

Xen Project Xen 4.0 and newer

Timeline

2026-07-28: disclosed: Public release of XSA-501
2026-07-28: patched

References

https://xenbits.xenproject.org/xsa/advisory-501.html

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