CVE-2026-23555

Name: CVE-2026-23555
Creator: NVD / NIST
Published: 2026-03-23T07:16:07.33+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 0.18%

Last modified Jun 17, 2026

CVE-2026-23555 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. Any guest issuing a Xenstore command accessing a node using the (illegal) node path "/local/domain/", will crash xenstored due to a clobbered error indicator in xenstored when verifying the node path. Note that the crash is forced via a failing assert() statement in xenstored. In case xenstored is being built with NDEBUG #defined, an unprivileged guest trying to access the node path "/local/domain/" will result in it no longer being serviced by xenstored, other guests (including dom0) will still be serviced, but xenstored will use up all cpu time it can get.. EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

Any guest issuing a Xenstore command accessing a node using the (illegal) node path "/local/domain/", will crash xenstored due to a clobbered error indicator in xenstored when verifying the node path. Note that the crash is forced via a failing assert() statement in xenstored. In case xenstored is being built with NDEBUG #defined, an unprivileged guest trying to access the node path "/local/domain/" will result in it no longer being serviced by xenstored, other guests (including dom0) will still be serviced, but xenstored will use up all cpu time it can get.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability

0.18%

7.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions
Xen	Xen	>= 4.18.0

References

https://xenbits.xenproject.org/xsa/advisory-481.htmlPatch, Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/03/17/7Mailing List, Patch, Third Party Advisory
http://xenbits.xen.org/xsa/advisory-481.htmlPatch, Vendor Advisory

Timeline

Published: Mar 23, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-23555?

How severe is CVE-2026-23555?

CVE-2026-23555 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2026-23555?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-23555?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST