CVE-2026-23555

Xenstored DoS by unprivileged domain

HIGH
7.1
CVSS Score
Published: March 23, 2026 at 06:57 AM UTC
Updated: June 17, 2026 at 10:21 AM UTC
1 product affected across 1 vendorXen

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Severity
HIGH7.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Xen· Xenwordpress-plugin
95%
v ≥ 4.18.0
Vendor states this is fixed in consult Xen advisory XSA-481 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

Mailing ListPatchThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/03/17/7
PatchVendor Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://xenbits.xen.org/xsa/advisory-481.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-617

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