CVE-2026-23558

highpriority · track · 0EPSS 0.001 · 2 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.12% (2nd) EPSS

CVSS 7.8 · high

Is it mine?

13 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.

cvss

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

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU

v3.17.8highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondaryexploitability 1.1 · impact 6

v3.17.1highCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:Usecondary · 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-362US

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:-
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:-
Open Source Xen≥ 4.2cert_bundDE
xen xen≥ 4.0.0nvdUScpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*

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 NVD CVE.org MITRE

published 2026-05-19modified 2026-10-14

references (6)

External citations — patches, advisories, analysis.

https://nvd.nist.gov/vuln/detail/CVE-2026-23558 cnnvd
https://xenproject.org/Patchcnnvd
https://xenbits.xenproject.org/xsa/advisory-486.html enisa_euvd
http://www.openwall.com/lists/oss-security/2026/04/28/13Mailing ListMitigationPatchThird Party Advisorynvd
http://xenbits.xen.org/xsa/advisory-486.htmlMitigationPatchVendor Advisorynvd
https://xenbits.xenproject.org/xsa/advisory-486.htmlMitigationPatchVendor Advisorynvd

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan