Bug 2428640 (CVE-2026-0665)

Summary: CVE-2026-0665 qemu-kvm: Heap off-by-one in KVM Xen PHYSDEVOP_map_pirq
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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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.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2428652, 2428653    
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Description OSIDB Bzimport 2026-01-12 10:48:19 UTC
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.

Patch:
https://lore.kernel.org/qemu-devel/13FE03BE60EA78D6+20260109023548.4047-1-vr@darknavy.com/

Credit: DARKNAVY (@DarkNavyOrg)