CVE-2026-109969
Description
A flaw was found in the clevis PKCS#11 pin. The clevis-pkcs11-afunix-socket-unlock daemon creates AF_UNIX sockets without explicit permission restrictions or peer credential verification. Under a permissive process umask, any local user can connect to the control socket and inject arbitrary device/key pairs, or connect to the data socket to receive LUKS passphrases.
Statement
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 under the default systemd UMask of 0022, sockets are created with mode 0755. AF_UNIX SOCK_STREAM requires write permission to connect, so unprivileged users cannot connect in the default configuration. The vulnerability is exploitable only when the process umask is permissive (e.g., in certain dracut initramfs configurations) or when the umask is explicitly set to 0000.
Mitigation
Configure the clevis-luks-pkcs11-askpass systemd service with a restrictive UMask by creating a service override using systemctl edit. Setting UMask to 0077 ensures the sockets are only accessible by root, preventing unauthorized connections.
This workaround only covers the systemd service path. The dracut initramfs code path is not covered by this mitigation.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | N/A | 4.7 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
Exposing critical functionality essentially provides an attacker with the privilege level of that functionality. The consequences will depend on the associated functionality, but they can range from reading or modifying sensitive data, accessing administrative or other privileged functionality, or possibly even executing arbitrary code.
Acknowledgements
This issue was discovered by Sergio Correia (Red Hat).
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