Executive brief
Gitea is a self-hosted Git service used for hosting and managing source code. A vulnerability in its Actions automation system allows an attacker who submits a pull request from a fork to bypass security restrictions and read the contents of other private repositories they should not have access to. This could lead to the exposure of sensitive source code or configuration files stored in private repositories on the same Gitea instance.
Technical details
The `GetActionsUserRepoPermission` function in `models/perm/access/repo_permission.go` fails to enforce a fork-PR discriminator in the collaborative-owner logic branch. While other access paths correctly use the `!task.IsForkPullRequest` guard, this specific branch allows an Actions task token generated for a fork PR to inherit code-read permissions for a target private repository if that repository has configured the base repository's owner as a collaborative owner. An attacker with the ability to trigger a workflow (e.g., a previously approved contributor) can use the task token to clone unrelated private repositories via git-HTTP. This is a read-only confidentiality breach fixed in version 1.27.0.
Affected products
- Gitea Gitea < 1.27.0
Timeline
- 2026-07-13: disclosed: Initial disclosure to vendor
- 2026-07-21: patched: Fixed in version 1.27.0
- 2026-07-21: advisory
References
- https://api.github.com/users/CassianStarck
- https://github.com/CassianStarck
- https://api.github.com/users/CassianStarck/gists%7B/gist_id%7D
- https://api.github.com/users/CassianStarck/repos
- https://avatars.githubusercontent.com/u/109820030?v=4
- https://api.github.com/users/CassianStarck/events%7B/privacy%7D