# CVE-2026-62425: Xen libfsimage buffer overflow in Rock Ridge CE record processing

Source: https://junglewise.ai/threats/cve-2026-62425-xen-libfsimage-buffer-overflow-in-rock-ridge-ce-record-processing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-28. Updated: 2026-07-28  
License: CC BY 4.0 with a link back

CVE-2026-62425 · Severity: info · CVSS 8.8 · Published 2026-07-28

A vulnerability in the Xen virtualization platform's disk image handling library could allow a malicious guest operating system to take control of the physical host server. By providing a specially crafted ISO disk image, an attacker can bypass security boundaries between the virtual machine and the host. This could lead to a total compromise of the host system, including access to data from other customers or tenants.

Technologies: [Xen Project Xen](https://junglewise.ai/threats/technologies/xen). Vendors: [Xen Project](https://junglewise.ai/threats/vendors/xen-project).

## Quick answers

**Is CVE-2026-62425 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-62425 being exploited in the wild.

**How severe is CVE-2026-62425?** Informational severity, with a CVSS score of 8.8, published 28 July 2026.

**Which products and versions are affected?** Xen Project Xen 3.2 and later.

**Is there a fix for CVE-2026-62425?** 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-2026-62425 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-62425?** 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 iso9660 driver within Xen's libfsimage library fails to validate lengths derived from attacker-controlled on-disk fields during directory and Rock Ridge/SUSP walks. Specifically, CVE-2026-62425 involves the Rock Ridge Continuation Entry (CE) record processing assuming valid size and offset values without verification. An attacker with the ability to provide a malicious ISO image to the pygrub bootloader can trigger a buffer overrun. This allows a guest to escalate privileges to the context of the domain construction tools, which typically results in full host compromise. A patch is available, and mitigations include running pygrub in a de-privileged mode or using alternative bootloaders like pvgrub.

## Affected products

- Xen Project Xen 3.2 and later

## Timeline

- 2026-07-28: advisory: XSA-497 published by Xen Project
- 2026-07-28: disclosed
- 2026-07-28: patched

## References

- [https://xenbits.xenproject.org/xsa/advisory-497.html](https://xenbits.xenproject.org/xsa/advisory-497.html)

## Related threats

- [Xen arbitrary read/write via grant copy caching](https://junglewise.ai/threats/cve-2026-102704-this-cna-information-record-relates-to-multiple-cves-the-text)
- [Xen hypervisor arbitrary read/write via grant copy](https://junglewise.ai/threats/cve-2026-102703-this-cna-information-record-relates-to-multiple-cves-the-text)
- [Xen VMX VMentry failure with branch tracing and blocked states](https://junglewise.ai/threats/cve-2026-79611-for-xsa-308-logic-was-introduced-as-vmx-vmentry-checks-do-not)
- [Xen XPTI privilege escalation on huge-memory systems](https://junglewise.ai/threats/cve-2026-79609-xpti-xen-page-table-isolation-was-introduced-to-mitigate-meltdown)
- [Xen ineffectual Zenbleed workaround on AMD x86](https://junglewise.ai/threats/cve-2026-79608-the-workaround-for-xsa-433-zenbleed-was-later-re-worked-to-better)