CVE-2026-23557 — MEDIUM (6.5)

Vulnerability 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 Score

6.5

MEDIUM

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

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Xen	Xen	>= 4.2.0

Related Weaknesses (CWE)

CWE-617

References

https://xenbits.xenproject.org/xsa/advisory-484.htmlPatchVendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/28/11Mailing ListPatchThird Party Advisory
http://xenbits.xen.org/xsa/advisory-484.htmlPatchVendor Advisory

FAQ

What is CVE-2026-23557?

CVE-2026-23557 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 happ...

How severe is CVE-2026-23557?

CVE-2026-23557 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-23557?

Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen.