CVE-2026-42490
domctl lock open to abuse
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.
INFO
Published Date :
June 18, 2026, 2:17 p.m.
Last Modified :
June 22, 2026, 6:38 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update the system to ensure fair lock acquisition.
- Apply patches that enforce permission checks before lock acquisition.
- Review Xenstore and domctl operation security.
- Consider alternative locking mechanisms if necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42490.
| URL | Resource |
|---|---|
| https://xenbits.xenproject.org/xsa/advisory-492.html |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42490 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42490
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42490 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42490 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-667 Added SSVC {'id': 'CVE-2026-42490', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-18T15:04:47.308725Z'} -
New CVE Received by [email protected]
Jun. 18, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Xen', 'product': 'Xen', 'versions': [{'status': 'unknown', 'version': 'consult Xen advisory XSA-492'}], 'defaultStatus': 'unknown'}] Added 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. Added Reference https://xenbits.xenproject.org/xsa/advisory-492.html