CVE-2026-119345: Cocos AI Intra-handshake attested TLS implementation is vulnerable to TOCTOU Attacks
Cocos AI is a confidential computing system for AI. Prior to 0.9.0, Cocos AI performs attestation only once when an attested TLS connection is established. An attacker who can modify the attester's workload code, memory-backed state, configuration, or attached devices after that check can keep the existing connection open while the peer continues trusting stale initial Evidence. This gap is especially significant for long-lived connections because the verifier has no mechanism to detect the changed state. This issue is fixed in version 0.9.0.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Cocos AIto a version that resolves this vulnerability.Fixed in 0.9.0
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Deployments using Cocos AI before 0.9.0 with attested TLS connections are affected. The risk is greatest for long-lived connections, where a peer may continue trusting evidence collected only when the connection was established.
What does an attacker need to exploit it?
The attacker must be able to modify the attester's workload code, memory-backed state, configuration, or attached devices after the initial attestation check. They can then retain the existing connection while the peer relies on stale initial evidence.
How can this be remediated?
Upgrade Cocos AI to version 0.9.0, which fixes the issue. The provided information does not identify a workaround for deployments that cannot upgrade immediately.