CVE-2026-109970

A flaw was found in the clevis PKCS#11 pin. The clevis-luks-pkcs11-askpin script writes the PKCS#11 token PIN in plaintext to a file without setting restrictive permissions. Under the default process umask, the file is world-readable. Additionally, the PIN file is not reliably cleaned up if the decryption script exits early, leaving the PIN accessible indefinitely.

The PKCS#11 clevis pin is an opt-in feature requiring explicit configuration (clevis luks bind pkcs11), PKCS#11 hardware, and activation of the corresponding systemd service or dracut module. Default clevis installations are not affected.

Red Hat rates this Moderate because exploitation requires local access during boot to catch a timing window, and the exposed credential is the PKCS#11 token PIN rather than the LUKS passphrase directly. An attacker with the PIN still requires physical access to the PKCS#11 token to perform private key operations.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Configure the clevis-luks-pkcs11-askpass systemd service with a restrictive UMask by creating a service override using systemctl edit. Setting UMask to 0077 prevents the PIN file from being readable by non-root users.

This workaround only covers the systemd service path. The dracut initramfs code path is not covered by this mitigation.