BlackTreeIndependent security intelligence

Full vulnerability report · 2026

CVE-2026-0665High confidence

Qemu-kvm: heap off-by-one in kvm xen physdevop_map_pirq

Unknown · Unknown

6.5MediumCVSS 3.1

Recommended action

Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified

Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu release	Source package	Vendor state	Fixed version	Evidence
Ubuntu 24.04 LTSnoble · standard archive	`qemu`	Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.	`1:8.2.2+ds-0ubuntu1.13`	Canonical record ↗Source updated 9 Sept 2026

Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current

CVE-2026-0665 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityqemu-kvm: Heap off-by-one in KVM Xen PHYSDEVOP_map_pirq

83 known not affected

The vendor explicitly states that these products are not affected by this CVE.

qemu-guest-agent as a component of Red Hat Enterprise Linux 10
qemu-img as a component of Red Hat Enterprise Linux 10
qemu-kvm as a component of Red Hat Enterprise Linux 10
qemu-kvm-audio-pa as a component of Red Hat Enterprise Linux 10
qemu-kvm-block-blkio as a component of Red Hat Enterprise Linux 10
qemu-kvm-block-curl as a component of Red Hat Enterprise Linux 10
qemu-kvm-block-rbd as a component of Red Hat Enterprise Linux 10
qemu-kvm-common as a component of Red Hat Enterprise Linux 10
qemu-kvm-core as a component of Red Hat Enterprise Linux 10
qemu-kvm-device-display-virtio-gpu as a component of Red Hat Enterprise Linux 10
qemu-kvm-device-display-virtio-gpu-ccw as a component of Red Hat Enterprise Linux 10
qemu-kvm-device-display-virtio-gpu-pci as a component of Red Hat Enterprise Linux 10

Summary: 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.
Remediation: No remediation text is recorded.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current

ENISA EUVD identifier

EUVD-2026-7934

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state: Present in the current official mapping
Known exploitation: Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score: Not supplied in the stored EUVD record
Advisory evidence: No linked advisory details stored yet

Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified

What, why and how

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.

What

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: local access → Out-of-bounds Write → disrupt the affected service
Attack surface: Local
Privileges required: Low: a basic authenticated account is required
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Changed: exploitation can affect a different security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-787 ↗
CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.

Denial of serviceCWE-787

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-7934Official EUVD mapping

0 linked advisory records.

Official EUVD record

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Fix not verified
Affected: 8.0.0 ≤ 10.2.0
Fixed: No fixed version is explicitly recorded in the structured CVE data.
Action: No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround: No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.

Evidence and provenance

Published 18 Feb 2026 · Last source change 18 Feb 2026, 21:27 UTC · CWE-787 · Out-of-bounds Write

CVE recordCVE.org · 5.2

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-08-14

European sourceENISA EUVD · EUVD-2026-7934

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceCNA

NVD statusNVD not scheduled

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

2026-02-18CVE published

ENISA EUVD · EUVD-2026-7934↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.