Quick answers
- Is CVE-2026-62423 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-62423 being exploited in the wild.
- How severe is CVE-2026-62423?
- Informational severity, with a CVSS score of 0, published 28 July 2026.
- Which products and versions are affected?
- Xen Project Xen 3.2 and later.
- Is there a fix for CVE-2026-62423?
- 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-2026-62423 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-62423?
- 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
The vulnerability is a buffer overrun located in the iso9660 driver of libfsimage. The root cause is the Rock Ridge extension loop assuming a valid inner record length derived directly from attacker-controlled on-disk fields without proper validation. An attacker with control over a guest VM can exploit this when the host uses pygrub to boot the guest's disk image. Successful exploitation allows for privilege escalation from the guest domain to the domain construction tools, typically resulting in host-level control. A patch is available from the Xen Project (XSA-497).
Affected products
- Xen Project Xen 3.2 and later
Timeline
- 2026-07-28: disclosed
- 2026-07-28: advisory
- 2026-07-28: patched