CVE-2026-99221. 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-2026-99221?
In the Linux kernel, the following vulnerability has been resolved:
keys/trusted_keys: return immediately after TPM unseal failure
trusted_tpm_unseal() proceeds to pcrlock() when the TPM unseal operation fails. If pcrlock() succeeds, its return value overwrites the unseal error, causing key instantiation to succeed.
Return immediately when unseal fails to preserve the original error.