CVE-2026-23557
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-23557
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-23557.html
Vendor advisory: af854a3a-2127-422b-91ae-364da2661108 — http://xenbits.xen.org/xsa/advisory-484.html
Vendor advisory: af854a3a-2127-422b-91ae-364da2661108 — http://www.openwall.com/lists/oss-security/2026/04/28/11
Vendor advisory: security@xen.org — https://xenbits.xenproject.org/xsa/advisory-484.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | affected | |
| debian | sid | affected | |
| debian | trixie | affected | |
References
CWEs
CWE-617
Verify integrity in audit chain (admin only). AS-IS.