CVE-2026-58510: Gitea GHSA-8fwc-qjw5-rvgp ClearRepoWatches Fix Not Applied Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-q423-49rw-g9mh",
  "modified" : "2026-07-21T21:51:41Z",
  "published" : "2026-07-21T21:51:41Z",
  "aliases" : [ "CVE-2026-58510" ],
  "summary" : "Gitea: GHSA-8fwc-qjw5-rvgp ClearRepoWatches fix not applied to API EditRepo path — sister code path retains stale watches on public->private",
  "details" : "## Summary\n\nGHSA-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(\"Gitea may send release notification emails for private repositories to users whose access has been revoked\", fix in PR #36319 / commit 8a98ac22) added `repo_model.ClearRepoWatches` as a defense for the state transition public→private.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.\n\nAs 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:\n\n- 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.\n- 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`.\n- Inflate the visible `NumWatches` counter on the repository.\n\n## Severity\n\nMedium — `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`\n\nSame 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.\n\nCWE-281 (Improper Preservation of Permissions), CWE-359 (Exposure of Private Personal Information), CWE-200 (Exposure of Sensitive Information).\n\n## Affected Versions\n\nEvery 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`.\n\n## Affected Component\n\n- `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`.\n- `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.\n\n## Steps to Reproduce\n\nThe bug is observable purely from static analysis; the live PoC is straightforward.\n\n1. Start a Gitea instance at any release from v1.25.4 onwards (verified static at HEAD `ef801bb6`).\n\n2. Create users `A` (org admin) and `B` (member). Create a public repository `A/proj`. As `B`, watch the repo:\n   ```\n   curl -u B:<token> -X PUT \"https://gitea.example.com/api/v1/repos/A/proj/subscription\"\n   ```\n\n3. As `A`, flip the repo to private via the REST API (not via the web UI):\n   ```\n   curl -u A:<token> -X PATCH \"https://gitea.example.com/api/v1/repos/A/proj\" \\\n        -H 'Content-Type: application/json' \\\n        -d '{\"private\": true}'\n   ```\n\n4. As `B`, list `B`'s watched repos with `private=true`:\n   ```\n   curl -u B:<token> \"https://gitea.example.com/api/v1/user/subscriptions\"\n   ```\n\n   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.\n\n5. 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`.\n\nThe asymmetry of outcomes between steps 4 and 5 — for the same state transition — is the gap.\n\n## Direct Evidence (no PoC needed)\n\n```\n$ gh api repos/go-gitea/gitea/contents/services/repository/repository.go \\\n    --jq .content | base64 -d | grep -n \"ClearRepoWatches\\|ClearRepoStars\" \n\n154:                  if err = repo_model.ClearRepoStars(ctx, repo.ID); err != nil {\n157:                  if err = repo_model.ClearRepoWatches(ctx, repo.ID); err != nil {  # MakeRepoPrivate\n273:                  if err = repo_model.ClearRepoStars(ctx, repo.ID); err != nil {  # updateRepository — ClearRepoWatches missing here\n```\n\nThe fix-author's own test file confirms the asymmetry:\n\n```\n$ gh api repos/go-gitea/gitea/contents/services/repository/repository_test.go --jq .content | base64 -d | grep -n \"Test.*VisibilityChanged\\|Test.*ClearsWatches\"\n\n44:func TestUpdateRepositoryVisibilityChanged(t *testing.T) {     # only checks act.IsPrivate\n73:func TestMakeRepoPrivateClearsWatches(t *testing.T) {           # checks watches are cleared\n```\n\n`TestUpdateRepositoryVisibilityChanged` explicitly calls `updateRepository(ctx, repo, true)` (line 53) and asserts `act.IsPrivate` (line 61) — but never verifies `GetRepoWatchersIDs` returns empty, while the parallel `TestMakeRepoPrivateClearsWatches` does. The test asymmetry mirrors the fix asymmetry.\n\n## Impact\n\n- An organization that uses [terraform-gitea](https://github.com/go-gitea/terraform-provider-gitea) or any other REST-API-driven automation to flip repositories private (the canonical IaC pattern) hits `updateRepository`, not `MakeRepoPrivate`.\n- An organization using the official Gitea SDK (`go-sdk`, `py-gitea`, etc.) or `curl` scripts to make repos private after an internal policy change hits the same path.\n- Multi-tenant Gitea-as-a-service operators with API-driven repository-lifecycle endpoints are exposed.\n\nStale watch rows leak through `GET /user/subscriptions` (with the watcher's own credentials), `GET /repos/{owner}/{repo}/subscribers` (stale `NumWatches` total), and become a re-leak surface for any future notification path that forgets the send-time access check.\n\n## Suggested Fix\n\nDrop-in mirror of the call already present in `MakeRepoPrivate`. In `services/repository/repository.go::updateRepository`, inside the existing `if repo.IsPrivate { ... }` branch (around line 265-276), add the `ClearRepoWatches` call directly after `ClearRepoStars`:\n\n```go\n// services/repository/repository.go\nfunc updateRepository(ctx context.Context, repo *repo_model.Repository, visibilityChanged bool) (err error) {\n    ...\n    if visibilityChanged {\n        ...\n        // If repo has become private, we need to set its actions to private.\n        if repo.IsPrivate {\n            _, err = e.Where(\"repo_id = ?\", repo.ID).Cols(\"is_private\").Update(&activities_model.Action{\n                IsPrivate: true,\n            })\n            if err != nil {\n                return err\n            }\n\n            if err = repo_model.ClearRepoStars(ctx, repo.ID); err != nil {\n                return err\n            }\n\n            // Match MakeRepoPrivate's behavior — see PR #36319 / GHSA-8fwc-qjw5-rvgp.\n            // Stale watch rows on a now-private repo leak repository metadata to ex-watchers\n            // via GET /user/subscriptions?private=true and through any future notification\n            // path that does not have a send-time access check.\n            if err = repo_model.ClearRepoWatches(ctx, repo.ID); err != nil {\n                return err\n            }\n        }\n        ...\n    }\n    ...\n}\n```\n\nRegression test (mirror of `TestMakeRepoPrivateClearsWatches`) to add to `services/repository/repository_test.go`:\n\n```go\nfunc TestUpdateRepositoryClearsWatchesOnVisibilityChange(t *testing.T) {\n    assert.NoError(t, unittest.PrepareTestDatabase())\n\n    repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})\n    assert.False(t, repo.IsPrivate)\n\n    watchers, err := repo_model.GetRepoWatchersIDs(t.Context(), repo.ID)\n    require.NoError(t, err)\n    require.NotEmpty(t, watchers)\n\n    repo.IsPrivate = true\n    assert.NoError(t, updateRepository(t.Context(), repo, true))\n\n    watchers, err = repo_model.GetRepoWatchersIDs(t.Context(), repo.ID)\n    assert.NoError(t, err)\n    assert.Empty(t, watchers)\n\n    updatedRepo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: repo.ID})\n    assert.Zero(t, updatedRepo.NumWatches)\n}\n```\n\nOptional belt-and-suspenders: an integration test against `PATCH /api/v1/repos/{owner}/{repo}` with body `{\"private\": true}` that exercises the entire API path through `routers/api/v1/repo/repo.go::Edit`.\n\n## Discovery Methodology\n\nThis finding follows the \"sister-fix-incomplete\" lens that has been productive across several recent reports: pick a recent advisory where the fix lands as a single PR touching one function, then grep the codebase for parallel call sites that should have received the same defense.\n\nFor Gitea:\n\n1. Enumerate recent advisories via `gh api graphql ... securityVulnerabilities(ecosystem: GO, package: code.gitea.io/gitea)`.\n2. GHSA-8fwc-qjw5-rvgp stood out because the description names a state transition (public→private) — a class of bug where the defense is typically wired into a single helper.\n3. `gh api repos/.../commits/8a98ac221 --jq '.files[] | .filename'` listed the fix files; `ClearRepoWatches` was added to one function.\n4. `grep -rn \"ClearRepoWatches\\|MakeRepoPrivate\"` revealed two functions in `services/repository/repository.go` that handle the state transition: `MakeRepoPrivate` (patched) and the lowercase sister `updateRepository` (unpatched).\n5. Walked the call chain from `routers/api/v1/repo/repo.go::Edit` to confirm the API path uses `updateRepository`, not `MakeRepoPrivate`.\n\n## Pre-emptive rebuttals\n\n- \"The send-time filter in `MailNewRelease` already blocks release-content disclosure\" — Correct, and acknowledged. The residual leak this report concerns is metadata via the `GET /user/subscriptions` endpoint and stale `NumWatches`. The send-time filter is a necessary but not sufficient defense; the `ClearRepoWatches` call is the persistence-side belt-and-suspenders that the original PR author explicitly added.\n- \"The web UI is the supported path; the API path is not in scope\" — The API is documented public surface (swagger spec in `templates/swagger/v1_json.tmpl`), Gitea ships official SDKs (`go-sdk`, `py-gitea`) that use exactly this path, and there is an official Terraform provider that exercises it. The existing fix is in a sister helper used by both paths' upstream helper — the fix author plainly intended to defend both.\n- \"AccessMode is `None` in the subscription response, so the client should infer no-access\" — The response still returns the full `Repository` payload including description, default branch, language, fork status, counts, mirror metadata, OriginalURL, license, etc. (see `services/convert/repository.go::innerToRepo` line 189-259). `AccessMode: 0` does not gate the metadata fields, only the `Permissions{Admin,Push,Pull}` triple.\n\n## References\n\n- GHSA-8fwc-qjw5-rvgp — the original advisory: https://github.com/go-gitea/gitea/security/advisories/GHSA-8fwc-qjw5-rvgp\n- PR #36319 \"clean watches when make a repository private and check permission when send release emails\" (commit `8a98ac221`)\n- PR #36959 \"Require additional user confirmation for making repo private\" (commit `943ff7523`) — the later refactor that did not propagate the cleanup\n- Patched function: `services/repository/repository.go::MakeRepoPrivate` (line 125, calls `ClearRepoWatches` line 157)\n- Unpatched sister: `services/repository/repository.go::updateRepository` (line 240, calls only `ClearRepoStars` line 273)\n- API entry: `routers/api/v1/repo/repo.go::Edit` → `updateBasicProperties` → `repo_service.UpdateRepository` → `updateRepository`\n- Test asymmetry: `services/repository/repository_test.go::TestMakeRepoPrivateClearsWatches` (covered) vs `TestUpdateRepositoryVisibilityChanged` (does not assert watches cleared)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "code.gitea.io/gitea"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.27.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/security/advisories/GHSA-q423-49rw-g9mh"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/go-gitea/gitea"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-281", "CWE-359" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-21T21:51:41Z",
    "nvd_published_at" : null
  }
}