Quick answers
- Is CVE-2026-62435 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-62435 being exploited in the wild.
- How severe is CVE-2026-62435?
- Informational severity, with a CVSS score of 8.8, published 28 July 2026.
- Which products and versions are affected?
- Xen Project Xen 4.0 onwards.
- Is there a fix for CVE-2026-62435?
- 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-2026-62435 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-62435?
- 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 version switching mechanism (specifically v1 to v2 transitions). The vulnerability occurs because the code drops and re-acquires the grant table lock, incorrectly assuming that table properties remain static during the unlocked window. An unprivileged multi-vCPU x86 guest can exploit this timing window to manipulate grant references. This can lead to host privilege escalation, information disclosure, or a denial of service. The issue affects all Xen versions from 4.0 onwards, provided grant table v2 is enabled and the guest is running on x86 architecture.
Affected products
- Xen Project Xen 4.0 onwards
Timeline
- 2026-07-28: disclosed
- 2026-07-28: advisory
- 2026-07-28: patched