Gitea's collaboration access-mode endpoint accepts the Owner access mode from an authenticated repository collaborator with Admin access. The collaborator can promote their effective permissions from Admin to Owner and then perform owner-only operations, including transferring the repository to their own account. This bypasses the intended boundary between repository administration and ownership.
https://github.com/go-gitea/gitea/security/advisories/GHSA-h62v-wmrr-5qjq
https://github.com/go-gitea/gitea/releases/tag/v1.27.2
https://github.com/go-gitea/gitea/pull/38895
https://github.com/go-gitea/gitea/pull/38894