Woodpecker CI: fork-approval gate bypassed by spoofing the git commit author name

Impact

Woodpecker checks its ApprovalAllowedUsers list against pipeline.Author, which for the GitLab driver comes from the commit author name in the webhook payload - a field GitLab does not verify. Anyone who can open a merge request from a fork sets that name to a trusted entry and the pipeline runs with no approval. The result is attacker-chosen pipeline steps executing on a Woodpecker agent and any CI secret exposed to that run being readable. Where those agents sit on GPU nodes to build or test accelerated images, this is arbitrary code execution on fleet hardware with the build identity attached, and the stolen secrets (registry pushes, cloud credentials, signing keys) extend the reach well past the one node. Gitea, Forgejo, GitHub and Bitbucket driver deployments are not affected.

Who can reach it

Remote, needs only the ability to open a merge request from a fork against a repository the Woodpecker server watches via the GitLab driver - i.e. any GitLab user who can fork it. No Woodpecker account required.

What to do

Upgrade the Woodpecker server to 3.15.0 or later and restart it; agents do not need replacing. Until then, empty ApprovalAllowedUsers on GitLab-backed repositories so every fork pipeline requires approval, and rotate any secret that fork pipelines could have read.

References

Related entries

• Renovate: unvalidated GitLab Link header redirects credential-bearing pagination requestsCVE-2026-88880 · Renovate (GitLab pagination, HTTP Link header host validation)Critical
• Renovate: unvalidated GitHub Link header sends host credentials to an attacker-controlled serverCVE-2026-88881 · Renovate (GitHub pagination, HTTP Link header host validation)Critical
• Renovate: NuGet datasource follows cross-origin Link pagination and leaks registry credentialsCVE-2026-88882 · Renovate (NuGet datasource registry pagination)Critical
• Renovate: Docker datasource follows cross-origin Link pagination and sends registry credentials to the attacker's hostCVE-2026-88887 · Renovate (container/Docker datasource registry pagination)Critical
• Moxa NPort W2150A / W2250A wireless device server: The device ships with an empty default password, so anyone who canCVE-2017-16727 · Moxa NPort W2150A / W2250A wireless device serverCritical
• Brocade Fabric OS (proxy service information disclosure): Unauthenticated remote attackers can obtain sensitiveCVE-2018-6440 · Brocade Fabric OS (proxy service information disclosure)Critical