CVE-2026-42490 | domctl lock open to abuse

[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.

Published: 2026-06-18 Last update: 2026-06-22 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42490 is rated Low Risk (29.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.20%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42490

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-23 — 0.20% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42490

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-42490

GitHub Security Advisory for CVE-2026-42490

GHSA-9xq7-8p44-p7p4 · Severity: medium — [This CNA information record relates to multiple CVEs; the text explains which aspects...

OS Trackers for CVE-2026-42490

vendor priority summary link
debian end-of-life CVE-2026-42490 end-of-life priority: Debian including 1 source packages (xen), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2026-42490
suse medium CVE-2026-42490 severity moderate: SUSE including 18 source package names (xen-4.17.6_12-150500.3.73.1, xen-4.18.5_18-150600.3.50.1, …), 43 product×package rows across 9 product lines (SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (9 product lines)): First Fixed 43. https://www.suse.com/security/cve/CVE-2026-42490/
ubuntu medium CVE-2026-42490 medium priority: Ubuntu including 1 source packages (xen), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-42490

Affected software / configurations for CVE-2026-42490

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-42490

cvelogic Threat Intelligence