CVE-2026-0665: Qemu-kvm: heap off-by-one in kvm xen physdevop_map_pirq

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-18 · updated 2026-06-17
Weakness: CWE-787

Description

An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption.

References

https://access.redhat.com/security/cve/CVE-2026-0665
https://bugzilla.redhat.com/show_bug.cgi?id=2428640

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