{"id":"PYSEC-2026-2745","summary":"Open WebUI: Read-Only Users Can Toggle Note Pin Status via Incorrect Permission Check (Write via Read-Only Access)","details":"### Summary\n\nThe `POST /api/v1/notes/{id}/pin` endpoint performs a write operation (toggling the `is_pinned` field) but only checks for `read` permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require `write` permission. All other write endpoints (update, delete, access/update) correctly check for `write` permission.\n\n### Details\n\n**Affected code: `backend/open_webui/routers/notes.py` lines 412-444**\n\n```python\n@router.post('/{id}/pin', response_model=Optional[NoteModel])\nasync def pin_note_by_id(...):\n    # ...\n    if user.role != 'admin' and (\n        user.id != note.user_id\n        and not await AccessGrants.has_access(\n            user_id=user.id,\n            resource_type='note',\n            resource_id=note.id,\n            permission='read',        # BUG: should be 'write'\n            db=db,\n        )\n    ):\n        raise HTTPException(...)\n    \n    note = await Notes.toggle_note_pinned_by_id(id, db=db)  # write operation\n```\n\n**Compare with update endpoint (correct, line 318-327):**\n```python\nasync def update_note_by_id(...):\n    # ...\n    and not await AccessGrants.has_access(\n        permission='write',        # correctly checks 'write'\n    )\n```\n\n### PoC\n\n**Environment:** Open WebUI v0.9.2, default configuration with notes sharing enabled.\n\n**Setup:**\n1. UserA creates a note\n2. UserA shares note with UserB with `read` permission via `POST /api/v1/notes/{id}/access/update` with `{\"access_grants\":[{\"principal_type\":\"user\",\"principal_id\":\"USERB_ID\",\"permission\":\"read\"}]}`\n\n**Test:**\n```bash\n# Step 1: UserB reads note (READ permission) -\u003e 200 OK, write_access: false\ncurl -s http://TARGET/api/v1/notes/$NOTE_ID \\\n  -H \"Authorization: Bearer $TOKEN_B\"\n# Result: 200 OK, \"write_access\": false\n\n# Step 2: UserB updates note (WRITE operation) -\u003e 403 Forbidden (correctly blocked)\ncurl -s -X POST http://TARGET/api/v1/notes/$NOTE_ID/update \\\n  -H \"Authorization: Bearer $TOKEN_B\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"title\":\"HACKED\",\"content\":\"pwned\",\"data\":{\"type\":\"note\"}}'\n# Result: 403 Forbidden\n\n# Step 3: UserB pins note (WRITE operation, but only checks READ) -\u003e 200 OK (BUG!)\ncurl -s -X POST http://TARGET/api/v1/notes/$NOTE_ID/pin \\\n  -H \"Authorization: Bearer $TOKEN_B\"\n# Result: 200 OK, \"is_pinned\": true\n\n# Step 4: UserB can toggle pin repeatedly\ncurl -s -X POST http://TARGET/api/v1/notes/$NOTE_ID/pin \\\n  -H \"Authorization: Bearer $TOKEN_B\"\n# Result: 200 OK, \"is_pinned\": false (toggled back)\n```\n\n**E2E Verified Result:**\n- Step 1: UserB reads note (READ) -\u003e 200 OK ✓\n- Step 2: UserB updates note (WRITE) -\u003e 403 Forbidden ✓ (correctly blocked)\n- Step 3: UserB pins note (WRITE via READ) -\u003e 200 OK, is_pinned: true ✗ (BUG)\n- Step 4: UserB toggles pin again -\u003e 200 OK, is_pinned: false ✗ (repeated write)\n\n### Impact\n\n- A user with only `read` access to a shared note can toggle its `is_pinned` status\n- This modifies the note's state without write authorization\n- The pin status change is visible to the note owner and all other users with access\n- Privilege escalation from read to write on the pin operation\n\n**Limitations:** Only affects the `is_pinned` boolean field. Cannot modify title, content, or access_grants. Requires at least read access via explicit sharing.\n\n### Fix\n\nOne-line fix — change `permission='read'` to `permission='write'` in `pin_note_by_id`:\n\n```python\n# backend/open_webui/routers/notes.py, line 437\n- permission='read',\n+ permission='write',\n```\n\nThis makes the pin endpoint consistent with update and delete endpoints.","aliases":["CVE-2026-45316","GHSA-jx2x-j75f-xq3j"],"modified":"2026-07-13T16:32:21.005788230Z","published":"2026-07-13T15:19:06.177623Z","references":[{"type":"WEB","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-jx2x-j75f-xq3j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45316"},{"type":"PACKAGE","url":"https://github.com/open-webui/open-webui"},{"type":"WEB","url":"https://github.com/open-webui/open-webui/releases/tag/v0.9.3"},{"type":"PACKAGE","url":"https://pypi.org/project/open-webui"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-jx2x-j75f-xq3j"}],"affected":[{"package":{"name":"open-webui","ecosystem":"PyPI","purl":"pkg:pypi/open-webui"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.3"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.10","0.5.11","0.5.12","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.5.2","0.5.20","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.15","0.6.16","0.6.18","0.6.19","0.6.2","0.6.20","0.6.21","0.6.22","0.6.23","0.6.24","0.6.25","0.6.26","0.6.26.dev1","0.6.27","0.6.28","0.6.29","0.6.3","0.6.30","0.6.31","0.6.32","0.6.33","0.6.34","0.6.35","0.6.36","0.6.37","0.6.38","0.6.39","0.6.4","0.6.40","0.6.41","0.6.42","0.6.43","0.6.5","0.6.6","0.6.6.dev1","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.8.0","0.8.1","0.8.10","0.8.11","0.8.12","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9","0.9.0","0.9.1","0.9.2"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/open-webui/PYSEC-2026-2745.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N"}]}