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

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.

Published: 2026-02-18 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-0665 is rated Low Risk (26.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-0665

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-19 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-0665

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.0 4.0 [email protected]

Weakness enumeration for CVE-2026-0665

OS Trackers for CVE-2026-0665

vendor priority summary link
debian unimportant CVE-2026-0665 unimportant priority: Debian including 1 source packages (qemu), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-0665
redhat medium — https://access.redhat.com/security/cve/CVE-2026-0665
suse medium CVE-2026-0665 severity moderate: SUSE including 377 source package names (13.2-9.16:libgcrypt20-1.10.3-2.1, 2.1.3-6.122:libgcrypt20-1.10.3-2.1, …), 1075 product×package rows across 63 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (63 product lines)): Fixed 596, Known Not Affected 439, First Fixed 40. https://www.suse.com/security/cve/CVE-2026-0665/
ubuntu medium CVE-2026-0665 medium priority: Ubuntu including 1 source packages (qemu), 9 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): not-affected 5, released 3, ignored 1. https://ubuntu.com/security/CVE-2026-0665

Affected software / configurations for CVE-2026-0665

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-0665

cvelogic Threat Intelligence