How severe is CVE-2026-0665?

CVE-2026-0665 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-0665 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-0665?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-0665 have an EU (EUVD) identifier?

Yes. CVE-2026-0665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7934.

When was CVE-2026-0665 published?

CVE-2026-0665 was published on 2026-02-18 and last updated on 2026-06-17.

CVE-2026-0665

CVE-2026-0665 is a medium-severity vulnerability with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-7934
Weakness: CWE-787
Published: 2026-02-18
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-0665?: 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.
How severe is CVE-2026-0665?: CVE-2026-0665 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-0665 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-0665?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-0665 have an EU (EUVD) identifier?: Yes. CVE-2026-0665 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7934.
When was CVE-2026-0665 published?: CVE-2026-0665 was published on 2026-02-18 and last updated on 2026-06-17.

References

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