VulnerabilityAnalyzed

CVE-2026-23557

Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering.

MEDIUM 6.5EPSS 0.16%

Does this matter?

Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.

Description

Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.

CVSS 3.1: 6.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS: 0.16% probability · 5th percentile
CISA KEV: Not listed
Weakness: CWE-617
Affected: xen/xen
Source: security@xen.org

References

https://xenbits.xenproject.org/xsa/advisory-484.htmlPatch, Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/28/11Mailing List, Patch, Third Party Advisory
http://xenbits.xen.org/xsa/advisory-484.htmlPatch, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.