Executive brief
Doco-CD is a continuous delivery tool that automatically deploys Docker services based on configuration stored in container image repositories. A flaw in how it validates container image signatures allows an attacker with write access to an image repository to bypass signature verification by embedding a configuration setting in a malicious image. This could enable deployment of untrusted or malicious code to production environments.
Technical details
Doco-CD contains a trust-boundary flaw in its OCI artifact verification logic that allows artifact-provided deployment configuration to influence the verification policy applied to that same artifact. The vulnerability exists when global OCI signature verification is enabled via the `OCI_TRUST_POLICY` setting. An attacker with write access to a configured OCI repository tag can publish an unsigned or improperly signed artifact containing `.doco-cd.yml` with `oci.verify: false`, which causes signature verification to be bypassed. This affects deployments that source configuration from artifact contents (poll/webhook flows without trusted inline overrides). The fix enforces strict trust boundaries: artifact-contained `.doco-cd.yml` is now treated as untrusted for policy-override decisions, and when `OCI_TRUST_POLICY.enabled` is true, per-deployment `oci.verify: false` cannot disable verification. Mitigations include sourcing deployment config from trusted inline configuration only, restricting write permissions on OCI repositories, and using immutable digest pinning.
Affected products
- Doco-CD Doco-CD prior to 0.90.1
Timeline
- 2026-09-11: disclosed