Keylime Verifier Hardcoded Nonce Enables TPM Quote Replay
CVE-2026-6420 Published on May 6, 2026
Keylime: keylime: security bypass due to hardcoded tpm quote nonce
A flaw was found in Keylime. An attacker with root access on an enrolled monitored machine, where the Keylime agent runs, can exploit a vulnerability in the Keylime verifier. The verifier uses a hardcoded challenge nonce for Trusted Platform Module (TPM) quote attestation instead of a cryptographically random value. This allows the attacker to stockpile valid TPM quotes and replay them to evade detection after compromising the system. This issue affects only the push model deployment.
Vulnerability Analysis
CVE-2026-6420 is exploitable with local system access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and a small impact on availability.
Timeline
Reported to Red Hat.
Made public. 20 days later.
Weakness Type
Use of Predictable Algorithm in Random Number Generator
The device uses an algorithm that is predictable and generates a pseudo-random number.
Products Associated with CVE-2026-6420
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