CVE-2026-62432

evtchn: Race between FIFO expand and reset

Published Jul 28, 2026 CVSS 3.1 · 7.3 High EPSS < 1% KEV · Not listed
Description
The EVTCHNOP_expand_array hypercall checks for whether FIFO event
channels are enabled, but without holding the correct lock. It can race
with EVTCHNOP_reset, resulting in dereferencing a NULL pointer.

Remediation

Vendor Workaround

There are no mitigations.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4818-1 xen security update
Debian DSA Debian DSA DSA-6424-1 xen security update
History
Type Values Removed Values Added
First Time appeared Xen
Xen xen
Vendors & Products Xen
Xen xen
Type Values Removed Values Added
Weaknesses CWE-362
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The EVTCHNOP_expand_array hypercall checks for whether FIFO event channels are enabled, but without holding the correct lock. It can race with EVTCHNOP_reset, resulting in dereferencing a NULL pointer.
Title evtchn: Race between FIFO expand and reset
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
XEN
Published
Updated
Jul 28, 2026, 4:33 PM
Reserved
Jul 14, 2026, 10:28 AM
Status
Deferred
Published
Jul 28, 2026, 1:19 PM
Modified
Jul 28, 2026, 5:16 PM