Quick answers
- Is CVE-2026-62430 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-62430 being exploited in the wild.
- How severe is CVE-2026-62430?
- Informational severity, with a CVSS score of 0, published 28 July 2026.
- Which products and versions are affected?
- Xen Project Xen 3.2 through 4.19.x.
- Is there a fix for CVE-2026-62430?
- 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-2026-62430 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-62430?
- 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 Xen's x86 vRTC emulation when accessing CMOS memory via indirect IO port pairs. The hypervisor caches a guest-chosen index but fails to implement necessary locking during certain operations. This allows a guest to modify the index after it has been validated but before it is used, resulting in a Time-of-Check Time-of-Use (TOCTOU) flaw that leads to an out-of-bounds read of Xen's internal array contents. The impact is limited to information disclosure of hypervisor data; it does not permit cross-guest data access. The vulnerability affects HVM guests; PV and PVH guests are not impacted.
Affected products
- Xen Project Xen 3.2 through 4.19.x
Timeline
- 2026-07-28: disclosed
- 2026-07-28: advisory
- 2026-07-28: patched