Xen Security Advisory 510 v3 (CVE-2026-79602) - x86: improper handling of HVM emulation return codes
Xen Project released XSA-510 (CVE-2026-79602) fixing mishandled HVM emulation return codes that let PCI-passthrough guests crash Xen.
Xen Security Advisory 510 v3 publicly discloses CVE-2026-79602, improper handling of HVM emulation return codes in the Xen hypervisor on x86. A guest with an assigned PCI device that has at least one BAR in the IO port space can trigger a BUG() in Xen. The advisory was released publicly as version 3.
- CVE-2026-79602 assigned to the HVM emulation return-code flaw
- Triggered via PCI device passthrough with an IO port space BAR
- Guest-triggerable BUG() crash condition in Xen on x86
- Published as public Xen Security Advisory XSA-510 v3
- CVEs
- CVE-2026-79602
- Vendors
- Xen Project
- Products
- Xen
- Organizations
- Xen Project
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2026-79602 | Guest-triggerable hypervisor DoS in Xen via PCI passthrough I/O port BARs | 8.8 | <1% |
From the original article
Posted by Xen . org security team on Sep 08 Xen Security Advisory CVE-2026-79602 / XSA-510 version 3 x86: improper handling of HVM emulation return codes UPDATES IN VERSION 3 ==================== Public release. ISSUE DESCRIPTION ================= A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.
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