CVE-2026-42489
CWE-667Published: June 18, 2026· Updated: Jun 22, 2026
Official Description
[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.
Technical Analysis
CVE-2026-42489 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.3.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (1)
Quick Facts
Related CVEs (CWE-667)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-42489 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts