Gitea: GHSA-8fwc-qjw5-rvgp ClearRepoWatches fix not applied to API EditRepo path — sister code path retains stale watches on public->private
Summary
GHSA-8fwc-qjw5-rvgp ("Gitea may send release notification emails for private repositories to users whose access has been revoked", fix in PR #36319 / commit 8a98ac22) added repo_model.ClearRepoWatches as a defense for the state transition public→private. The cleanup was wired into services/repository/repository.go::MakeRepoPrivate only. The sister helper services/repository/repository.go::updateRepository — which is the function used by the API path PATCH /api/v1/repos/{owner}/{repo} — was not patched and still calls ClearRepoStars only.
As a result, when a public repository is flipped to private via the REST API (rather than via the web Settings → Danger Zone UI), the watch records persist. Affected users can:
- See the now-private repository in
GET /api/v1/user/subscriptions?private=true along with its full Repository JSON (description, default branch, language, fork status, counts, mirror metadata, license list, etc.) — even though they have no access to the repository. - Have their stale watch records re-leak content through any future notification path that does not include the send-time
CheckRepoUnitUser check that was added to services/mailer/mail_release.go. - Inflate the visible
NumWatches counter on the repository.
Severity
Medium — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Same impact class as the original GHSA-8fwc-qjw5-rvgp (which was classified Medium). The send-time mail filter added in the same PR mitigates the release-content disclosure vector. The residual leak is repo metadata via the subscriptions endpoint and stale watcher counts.
CWE-281 (Improper Preservation of Permissions), CWE-359 (Exposure of Private Personal Information), CWE-200 (Exposure of Sensitive Information).
Affected Versions
Every release starting from v1.25.4 (the release shipping the original GHSA-8fwc-qjw5-rvgp fix) through HEAD (master @ ef801bb6, 2026-05-16). The follow-up refactor in commit 943ff752 (PR #36959, 2026-03-24) which merged MakeRepoPublic+MakeRepoPrivate did not propagate the ClearRepoWatches call to updateRepository.
Affected Component
services/repository/repository.go:240-302 — func updateRepository(ctx, repo, visibilityChanged bool), the sister helper called via the API path. Clears stars on line 273 but never calls ClearRepoWatches.routers/api/v1/repo/repo.go::Edit (line 573) → updateBasicProperties (line 678-697) → repo_service.UpdateRepository(ctx, repo, visibilityChanged) (line 726) — the API path that exercises the sister helper.
Steps to Reproduce
The bug is observable purely from static analysis; the live PoC is straightforward.
1. Start a Gitea instance at any release from v1.25.4 onwards (verified static at HEAD ef801bb6).
2. Create users A (org admin) and B (member). Create a public repository A/proj. As B, watch the repo:
```
curl -u B:<token> -X PUT "https://gitea.example.com/api/v1/repos/A/proj/subscription"
```
3. As A, flip the repo to private via the REST API (not via the web UI):
```
curl -u A:<token> -X PATCH "https://gitea.example.com/api/v1/repos/A/proj" \
-H 'Content-Type: application/json' \
-d '{"private": true}'
```
4. As B, list B's watched repos with private=true:
```
curl -u B:<token> "https://gitea.example.com/api/v1/user/subscriptions"
```
The now-private repo A/proj is returned in B's subscription list, with the full Repository payload — including description, default_branch, language, topics, license, fork/branch/issue/release counts, etc.
5. Compare with the web-UI path (which IS patched). As A, flip a different public repo A/proj2 to private via Settings → Danger Zone → "Make this repository private" (which calls repo_service.MakeRepoPrivate). Verify B's subscription list no longer contains A/proj2.
The asymmetry of outcomes between steps 4 and 5 — for the same state transition — is the gap.
Direct Evidence (no PoC needed)
```
$ gh api repos/go-gitea/gitea/contents/services/repository/repository.go \
--jq .content | base64 -d | grep -n "ClearRepoWatches\|ClearRepoStars"
154: if err = repo_model.ClearRepoStars(ctx, repo.ID); err != nil {
157: if err = repo_model.ClearRepoWatches(ctx, repo.ID); err != nil { # MakeRepoPrivate
273: if err = repo_model.ClearRepoStars(ctx, repo.ID); err != nil { # updateRepository — ClearRepoWatches missing here
```
The fix-author's own test file confirms the asymmetry:
```
$ gh api repos/go-gitea/gitea/contents/services/repository/repository_test.go --jq .content | base64 -d | grep -n "Test.*VisibilityChanged\|Test.*ClearsWatches"
44:func TestUpdateRepositoryVisibilityChanged(t *testing.T) { # only checks act.IsPrivate
73:func TestMakeRepoPrivateC
