GHSA-777r-4v59-6486: Gitea: Permanent Fork PR Workflow Approval Gate Bypass

| Field | Value | |-------|-------| | Identifier (researcher-assigned) | GITEA-2026-004 | | Product | Gitea (self-hosted Git service) | | Component | Gitea Actions — fork pull request approval gate | | Affected versions | All Gitea releases v1.20.0 and later, including the latest main (1.27.0+dev-289-gb7e95cc48c). The buggy logic was introduced in commit edf98a2dc3 — *"Require approval to run actions for fork pull request (#22803)"*, 2023-02-24 — and has shipped unchanged since. | | Fixed in | not yet (this disclosure) | | Authentication required | Yes — one unprivileged Gitea account capable of forking the target repository (the default ability for every authenticated user) | | User interaction required | Exactly once — a repository administrator must approve a single benign fork PR's workflow run from the attacker. After that, *no further interaction is ever required* for any future fork PR from the same attacker on the same repository. | | Discovered by | Prakhar Porwal — prakharporwal2004@gmail.com | | Live-verified on | Gitea main at commit b7e95cc48cc0e0d6fe24c89bb83da5b84a74490f, 2026-05-24 | 1. Executive summary Gitea Actions enforces an approval gate on workflow runs triggered by fork pull requests, so that an untrusted contributor cannot execute arbitrary workflow YAML on the maintainer's runner infrastructure without explicit consent. The gate is implemented by ifNeedApproval() in services/actions/notifier_helper.go. Its final clause skips the gate whenever the triggering user has any previously-approved run in the same repository: // services/actions/notifier_helper.go:423-433 if count, err := db.Countactions_model.ActionRun; err != nil { return false, fmt.Errorf("CountRuns: %w", err) } else if count > 0 { log.Trace("do not need approval because user %d has been approved before", user.ID) return false, nil } The check is scoped to (repo_id, trigger_user_id) only. It does not consider the pull request, the head commit, the workflow file contents, or a