CVE-2026-23556

criticalpriority · track · 0EPSS 0.001 · 3 %ileDEEU

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.14% (3rd) EPSS

CVSS 9.4 · critical

Is it mine?

13 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · cert_bund

EPSS · scored 2026-10-28

When oxenstored is tearing a domain down, the node data is cleaned up but the usage counts are leaked. When the domain ID is eventually reused, the new domain can create fewer nodes before beeing deemed to be over quota.

cvss

Technical severity, 0–10. One row per scoring source.

9.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.6–9.4

v4.09.4criticalCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:Hsecondary · ENISA EU

v4.09.4criticalCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · security@xen.org

v4.07.6highCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-281US

affected products (13)

Products and version ranges known to be affected.

Citrix Systems XenServer 8.4all versionscert_bundDEcpe:/a:citrix:xenserver:8.4
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Dell Avamarall versionscert_bundDEcpe:/a:dell:avamar:-
Dell NetWorkerall versionscert_bundDEcpe:/a:dell:networker:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
IBM QRadar SIEMall versionscert_bundDEcpe:/a:ibm:qradar_siem:-
IBM Security Verify Accessall versionscert_bundDEcpe:/a:ibm:security_verify_access:-
Open Source Xen XSA-419all versionscert_bundDEcpe:/o:xen:xen:xsa-419
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Xen oxenstored≤ allenisa_euvdEU

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1306Xen und Citrix Systems XenServer: Mehrere SchwachstellenDeutsch2026-04-28csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Xen und Citrix Systems XenServer ausnutzen, um seine Privilegien zu erhöhen, Sicherheitsmaßnahmen zu umgehen, Daten zu verändern und offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund NVD CVE.org MITRE

published 2026-07-09modified 2026-10-25

references (8)

External citations — patches, advisories, analysis.

scry

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