{"id":"CVE-2026-59222","aliases":["GHSA-gh7p-78x6-jw6m","PYSEC-2026-3598"],"url":"https://o3.security/vulnerability/CVE-2026-59222","summary":"Open WebUI: /api/v1/channels/{id}/members exposes full user model including sensitive credentials","details":"### Summary\n\nThe channel members endpoint serializes and returns **full user models** for channel participants, including settings objects. A normal user in a DM can retrieve admin-only sensitive configuration such as webhook URLs and tool server key material (`settings.ui.toolServers[].key`), which is not available via standard user info APIs.\n\n### Details\n\nThe endpoint GET `/api/v1/channels/{id}/members` returns the full serialized user model for every member in the channel. In both the DM and non-DM code paths, the handler constructs the response with `[UserModelResponse(**user.model_dump(), is_active=...)]` and returns it as the users list. Because `UserModel` (`models/users.py`) includes a settings object (`UserSettings`) and arbitrary UI configuration (`settings.ui`), the endpoint exposes other users' sensitive configuration to any channel participant.\n\nPractically, a regular user who participates in a DM or group can call `/api/v1/channels/{id}/members` and receive other members' settings, including admin-only details such as webhook notification URLs and tool server configuration, including credential fields like `settings.ui.toolServers[].key`. These values are not returned by the normal user profile endpoints (e.g., `/api/v1/users/{user_id}/info`).\n\n### PoC\n\n1. Start a local Open WebUI instance\n2. Log in as admin and in the Admin Panel, go to Settings -> General and check *Channels (Beta)*, then press Save.\n3. Create a low-privilege user in the Users tab\n4. Click on the admin's profile bottom left, Settings and Integrations. Then click the `+` after *Manage Tool Servers* to add some tool server with a secret Bearer token (eg. `KEY`)\n5. Log in as the attacker with the low-privilege account and create a new Direct Message channel with the admin user:\n\n<img width=\"690\" height=\"383\" alt=\"image\" src=\"https://github.com/user-attachments/assets/70208661-a0db-4457-9984-119056ca3daf\" />\n\n7. After creating, open DevTools with F12 and go to the Network tab. Then in the DM UI click on the *Users* icon top right to see the members. In the network tab, this should have triggered a `/api/v1/channels/{id}/members` request which responds with the `settings` key including `toolServers` and `key` values:\n\n<img width=\"1642\" height=\"577\" alt=\"image\" src=\"https://github.com/user-attachments/assets/6639d982-a156-4e8b-861e-587d86d9b152\" />\n\nThe attacker has now leaked the admin's bearer token for the toolserver they configured.\n\n### Impact\n\nConditions for exploit: channels are enabled and an attacker has a low-privilege account.\n\nWebhook URLs and tool server configurations (including bearer keys) can be exfiltrated from any user.\n\n### Original Agent Report\n\n<img width=\"400\" alt=\"app aikido dev_ai-pentests_projects_116389_assessments_019d67d4-81c8-7dd2-bb9e-0a4a774b2c78_issues_sidebarIssue=20440423 (4)\" src=\"https://github.com/user-attachments/assets/8415553a-9f1e-4f73-929c-aa0d18a101ca\" />","published":"2026-07-09T16:59:10.208Z","modified":"2026-10-21T02:31:00.427392997Z","cvss":null,"epss":{"score":0.00322,"percentile":0.25304,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"open-webui","fixedVersion":"0.10.0"}],"fix":{"url":"https://github.com/open-webui/open-webui/commit/fbcdcf146b99b5002705060a8243eee769108f9e","label":"open-webui/open-webui@fbcdcf1"},"references":[{"type":"WEB","url":"https://github.com/open-webui/open-webui/releases/tag/v0.10.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59222.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-gh7p-78x6-jw6m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59222"},{"type":"FIX","url":"https://github.com/open-webui/open-webui/commit/fbcdcf146b99b5002705060a8243eee769108f9e"},{"type":"PACKAGE","url":"https://github.com/open-webui/open-webui"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:31:00.427392997Z"}}