Vulnerability in Xen
CVE-2026-23555
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (6.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Xen — versions consult Xen advisory XSA-481
Weakness classification (CWE)
References
- xenbits.xenproject.org/xsa/advisory-481.html (Patch, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Patch, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-23555?
- CVE-2026-23555 is a high-severity vulnerability in Xen, classified under Reachable Assertion. CVSS score: 7.1/10. Published 2026-03-23.
- How severe is CVE-2026-23555?
- High severity. CVSS v3 base score is 7.1 out of 10.