CVE-2026-42490 — domctl lock open to abuse

Description (CNA)

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To create and manage guests, domctl operations are used by the control domain, a possible Xenstore domain, or by a domain controlling a particular guest. Some of these operations may not be executed in parallel, so a system-wide lock is used. The way that lock is acquired is, however, not providing any fairness. This is CVE-2026-42489. Furthermore, with XSM/Flask in use, the lock acquire will, for some operations, occur ahead of any permission checking. This is CVE-2026-42490.

Affected (CNA)

Vendor / product	Versions
Xen / Xen	unknown consult Xen advisory XSA-492

CWE

No CWE identifiers supplied.

References

https://xenbits.xenproject.org/xsa/advisory-492.html

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.