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fix(actions): deny fork-PR cross-repo access via collaborative owner - #38214
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bircni merged 3 commits intoJun 28, 2026
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The collaborative-owner branch in GetActionsUserRepoPermission granted code-read to a target private repository whenever its Actions config trusted the task repo's owner, but unlike every sibling path it did not check task.IsForkPullRequest. An attacker-controlled fork-PR workflow could therefore clone a third private repository it has no rights to. Add the same fork-PR guard the sibling checkSameOwnerCrossRepoAccess enforces, and add a regression test covering both the legitimate non-fork grant and the fork-PR denial. Assisted-by: Claude:claude-opus-4-8
lunny
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Jun 25, 2026
TheFox0x7
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Jun 28, 2026
bircni
enabled auto-merge (squash)
June 28, 2026 10:08
zeekay
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Jul 26, 2026
…o-gitea#38214) ### What `GetActionsUserRepoPermission` (`models/perm/access/repo_permission.go`) decides whether an Actions task token may access a target repo. Its cross-repo branches each enforce a fork-PR discriminator — except the collaborative-owner branch, which was missing the `!task.IsForkPullRequest` guard that its sibling `checkSameOwnerCrossRepoAccess` has. As a result, when a private repo **B** lists owner **A** as a collaborative owner, an attacker-controlled fork pull-request workflow whose base repo is owned by A was granted code-read on B — i.e. the fork's workflow could clone a third private repository it has no rights to (read-only confidentiality breach). ### Fix Add the same fork-PR guard the sibling path already enforces: ```go if taskRepo.IsPrivate && !task.IsForkPullRequest { actionsUnit := repo.MustGetUnit(ctx, unit.TypeActions) if actionsUnit.ActionsConfig().IsCollaborativeOwner(taskRepo.OwnerID) { return maxPerm, nil } } ```
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What
GetActionsUserRepoPermission(models/perm/access/repo_permission.go) decides whether an Actions task token may access a target repo. Its cross-repo branches each enforce a fork-PR discriminator — except the collaborative-owner branch, which was missing the!task.IsForkPullRequestguard that its siblingcheckSameOwnerCrossRepoAccesshas.As a result, when a private repo B lists owner A as a collaborative owner, an attacker-controlled fork pull-request workflow whose base repo is owned by A was granted code-read on B — i.e. the fork's workflow could clone a third private repository it has no rights to (read-only confidentiality breach).
Fix
Add the same fork-PR guard the sibling path already enforces: