7.1

CVE-2026-23555: Xenstored DoS by unprivileged domain

Analyzed
AliasesALPINE-CVE-2026-23555UBUNTU-CVE-2026-23555DEBIAN-CVE-2026-23555
Published 23-03-2026Last modified 23-03-2026

Vulnerability summary

CVE-2026-23555 is a high (CVSS 7.1) Reachable Assertion vulnerability in xen. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.1, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 3
OPENSUSE-SU-2026:10457-1SUSE-SU-2026:0908-1SUSE-SU-2026:1093-1

Timeline

  1. 23-03-2026
    PublishedVulnerability first disclosed.
  2. 23-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.18% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • xen≥ 4.18.0, < 4.18.5-r5 | ≥ 4.18.0, < 4.19.4-r2 | ≥ 4.18.0, < 4.20.2-r2 | ≥ 4.18.0, < 4.21.0-r3
Debian1 product
  • xen< 4.20.3+127-gc42374a105-0+deb13u1 | < 4.20.3+127-gc42374a105-1
Ubuntu1 product
  • xenAll versions (No fix recorded)
Xen1 product
  • xen≥ 4.18.0 (No fix recorded)

4 vendors · 4 products

References

8 links