CVE-2026-99245. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Nov 4, 2026
Release Notes
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-99245?
In the Linux kernel, the following vulnerability has been resolved:
KEYS: Fix key_reject_and_link() race with keyring restriction
The restrict_link check in key_reject_and_link() is done before taking the keyring semaphore, racing with a concurrent keyring_restrict() that installs the restriction while holding the semaphore in write mode.
Move the check to after __key_link_lock(), so it is done under the semaphore, matching the pattern used in __key_create_or_update().