{
  "affected": [
    {
      "affectedData": [
        {
          "product": "open-webui",
          "vendor": "open-webui",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.9.5, \u003c 0.10.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 before 0.10.0, any authenticated user can overwrite the content of a message in a channel they do not belong to (including private and DM channels) by sending a chat completion request with a channel:-prefixed chat_id and a target message_id. The channel: path routes pipeline output through _make_channel_emitter, which writes to the Messages table using the caller-supplied message_id without binding it to the channel. This issue is fixed in version 0.10.0."
    }
  ],
  "id": "CVE-2026-59714",
  "lastModified": "2026-09-18T20:09:01.757",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-59714",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-14T17:39:19.896564Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-13T20:17:23.280",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/open-webui/open-webui/commit/ac3449cac91e62b08a7c28e54fcd044d14dea791"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/open-webui/open-webui/pull/26385"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/open-webui/open-webui/releases/tag/v0.10.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-x2ff-v5v8-m75m"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-862"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "open-webui"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.9.5"
            },
            {
              "fixed": "0.10.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59714"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T17:01:07Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Summary\n\nAny authenticated user can overwrite the content of a message in a channel they do not belong to (including private and DM channels) by sending a chat completion request with a `channel:`-prefixed `chat_id` and a target `message_id`. The `channel:` path routes pipeline output through `_make_channel_emitter`, which writes to the `Messages` table using the caller-supplied `message_id` without binding it to the channel.\n\nThis advisory consolidates two filings of the same flaw: the original single-model form, and a multimodel `message_ids` variant that survives the partial fix shipped in v0.9.6 (see \"Fix status\" below).\n\n## Details (as introduced in v0.9.5)\n\nWhen a user submits a chat completion request with a `chat_id` starting with `channel:`, three authorization gaps combined in v0.9.5:\n\n1. **Ownership check skipped** (`main.py`): the `channel:` prefix caused the entire ownership/membership verification block to be skipped, with no channel membership/write check replacing it.\n\n```python\nif not chat_id.startswith(\u0027local:\u0027) and not chat_id.startswith(\u0027channel:\u0027):  # temporary/channel chats are not stored\n    if is_new_chat:\n        ...\n    else:\n        if not await Chats.is_chat_owner(chat_id, user.id) and user.role != \u0027admin\u0027:\n            raise HTTPException(...)\n```\n\n2. **Message ID from user input**: `id` (and each value of the multimodel `message_ids` map) comes directly from the request body and is passed as `message_id` to the channel emitter.\n\n3. **Unchecked database write** (`socket/main.py` `_make_channel_emitter`):\n\n```python\nasync def _make_channel_emitter(request_info):\n    channel_id = request_info[\u0027chat_id\u0027].removeprefix(\u0027channel:\u0027)\n    message_id = request_info[\u0027message_id\u0027]  # user-supplied\n    ...\n    await Messages.update_message_by_id(message_id, update_form)  # no channel/user authz\n```\n\n`Messages.update_message_by_id` performs a direct primary-key update with no `channel_id`/`user_id` validation.\n\n## Fix (shipped in v0.10.0)\n\nv0.9.6 added a channel gate to the `channel:` branch (PR #24725) that closed the single-model path, but it validated only the first entry of the multimodel `message_ids` map, leaving the multimodel fan-out exploitable. v0.10.0 closes the remaining gap with two layers:\n\n1. **Request-time per-entry validation** (`backend/open_webui/main.py`): every entry of `message_ids` is validated against the target channel, not just the first; any entry whose target message does not belong to the channel in `chat_id` is rejected.\n2. **Fail-closed emitter** (`backend/open_webui/socket/main.py`, `_make_channel_emitter`): before writing, it re-reads the target message and returns without writing unless `msg.channel_id` matches the channel derived from `chat_id`. A missing or mismatched message is a no-op, so a write can no longer land in a channel the caller does not target.\n\n## PoC\n\nSingle-model (fixed in v0.9.6):\n\n```bash\ncurl -X POST http://target:8080/api/chat/completions \\\n  -H \"Authorization: Bearer $USER_JWT\" -H \"Content-Type: application/json\" \\\n  -d \u0027{\n    \"model\": \"llama3\", \"stream\": true,\n    \"chat_id\": \"channel:any-channel-uuid-here\",\n    \"id\": \"target-message-uuid-to-overwrite\",\n    \"messages\": [{\"role\": \"user\", \"content\": \"Repeat exactly: This message has been tampered with\"}]\n  }\u0027\n```\n\nMultimodel (still works on v0.9.6):\n\n```json\nPOST /api/chat/completions\n{\n  \"chat_id\": \"channel:\u003cattacker_channel_id\u003e\",\n  \"message_ids\": {\n    \"model-a\": \"\u003cmessage_id_in_attacker_channel\u003e\",\n    \"model-b\": \"\u003cvictim_channel_message_id\u003e\"\n  },\n  \"messages\": [{\"role\": \"user\", \"content\": \"...\"}]\n}\n```\n\nThe first id passes channel scope validation; the second id is used by the per-model fan-out and overwrites the victim-channel message (with model output, or the provider-error string on a deterministic error). Even a failing model call writes error content to the target message.\n\n## Impact\n\n**Message integrity destruction:** an authenticated user can overwrite a message in a channel they cannot access, regardless of membership. The overwritten message retains the original author attribution while displaying attacker-chosen content (**impersonation**). Private channels, DM channels, and channels the attacker has no access to are all affected; the REST channel routes correctly return 403 for the same attacker, so the bypass is specific to the chat-completion channel pipeline.\n\n## Affected versions\n\n- Single-model path: introduced in commit `0037baeb2` (v0.9.5), fixed in v0.9.6 (#24725).\n- Multimodel `message_ids` path: present from v0.9.6, fixed in v0.10.0.\n- Consolidated Affected: `\u003e= 0.9.5, \u003c 0.10.0`. Patched: `\u003e= 0.10.0`.\n\n## Distinction from existing CVEs\n\nCVE-2026-45385 (GHSA-wwhq-cx22-f7vv) covered IDOR in the REST endpoint `POST /channels/{id}/messages/{message_id}/update` (`routers/channels.py`); its fix (commit `f5e110f`) only touched `channels.py`. This finding uses a different code path (`POST /api/chat/completions` with `chat_id: \"channel:\u003cid\u003e\"` \u2192 `main.py` \u2192 `socket/main.py:_make_channel_emitter`), untouched by that fix.\n\n## Suggested fix\n\nValidate **every** value in `message_ids` against the channel (not just the first), rejecting any whose target message does not belong to the channel in `chat_id`. Additionally, make `_make_channel_emitter` fail closed: re-check that the target message\u0027s `channel_id` matches the channel before calling `Messages.update_message_by_id`, treating a missing or mismatched message as an error/no-op.\n\n## Consolidation\n\nPer Open WebUI\u0027s Report Handling policy this advisory consolidates independent reports of the same chat-completions channel-overwrite flaw:\n\n- Single-model cross-channel overwrite via the `channel:` path: @sfwani (earliest filing).\n- Multimodel `message_ids` fan-out variant that bypasses the v0.9.6 first-id-only gate: @DavidCarliez.\n\nOne CVE for the consolidated advisory.",
  "id": "GHSA-x2ff-v5v8-m75m",
  "modified": "2026-07-24T17:01:07Z",
  "published": "2026-07-24T17:01:07Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-x2ff-v5v8-m75m"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/commit/33e4e0dcc43afcca80f9c635d762cdc76c768ba9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/commit/ac3449cac91e62b08a7c28e54fcd044d14dea791"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-webui/open-webui"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/releases/tag/v0.10.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids)"
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "open-webui",
        "purl": "pkg:pypi/open-webui"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.9.5"
            },
            {
              "fixed": "0.10.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.5",
        "0.9.6"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59714",
    "GHSA-x2ff-v5v8-m75m"
  ],
  "details": "## Summary\n\nAny authenticated user can overwrite the content of a message in a channel they do not belong to (including private and DM channels) by sending a chat completion request with a `channel:`-prefixed `chat_id` and a target `message_id`. The `channel:` path routes pipeline output through `_make_channel_emitter`, which writes to the `Messages` table using the caller-supplied `message_id` without binding it to the channel.\n\nThis advisory consolidates two filings of the same flaw: the original single-model form, and a multimodel `message_ids` variant that survives the partial fix shipped in v0.9.6 (see \"Fix status\" below).\n\n## Details (as introduced in v0.9.5)\n\nWhen a user submits a chat completion request with a `chat_id` starting with `channel:`, three authorization gaps combined in v0.9.5:\n\n1. **Ownership check skipped** (`main.py`): the `channel:` prefix caused the entire ownership/membership verification block to be skipped, with no channel membership/write check replacing it.\n\n```python\nif not chat_id.startswith(\u0027local:\u0027) and not chat_id.startswith(\u0027channel:\u0027):  # temporary/channel chats are not stored\n    if is_new_chat:\n        ...\n    else:\n        if not await Chats.is_chat_owner(chat_id, user.id) and user.role != \u0027admin\u0027:\n            raise HTTPException(...)\n```\n\n2. **Message ID from user input**: `id` (and each value of the multimodel `message_ids` map) comes directly from the request body and is passed as `message_id` to the channel emitter.\n\n3. **Unchecked database write** (`socket/main.py` `_make_channel_emitter`):\n\n```python\nasync def _make_channel_emitter(request_info):\n    channel_id = request_info[\u0027chat_id\u0027].removeprefix(\u0027channel:\u0027)\n    message_id = request_info[\u0027message_id\u0027]  # user-supplied\n    ...\n    await Messages.update_message_by_id(message_id, update_form)  # no channel/user authz\n```\n\n`Messages.update_message_by_id` performs a direct primary-key update with no `channel_id`/`user_id` validation.\n\n## Fix (shipped in v0.10.0)\n\nv0.9.6 added a channel gate to the `channel:` branch (PR #24725) that closed the single-model path, but it validated only the first entry of the multimodel `message_ids` map, leaving the multimodel fan-out exploitable. v0.10.0 closes the remaining gap with two layers:\n\n1. **Request-time per-entry validation** (`backend/open_webui/main.py`): every entry of `message_ids` is validated against the target channel, not just the first; any entry whose target message does not belong to the channel in `chat_id` is rejected.\n2. **Fail-closed emitter** (`backend/open_webui/socket/main.py`, `_make_channel_emitter`): before writing, it re-reads the target message and returns without writing unless `msg.channel_id` matches the channel derived from `chat_id`. A missing or mismatched message is a no-op, so a write can no longer land in a channel the caller does not target.\n\n## PoC\n\nSingle-model (fixed in v0.9.6):\n\n```bash\ncurl -X POST http://target:8080/api/chat/completions \\\n  -H \"Authorization: Bearer $USER_JWT\" -H \"Content-Type: application/json\" \\\n  -d \u0027{\n    \"model\": \"llama3\", \"stream\": true,\n    \"chat_id\": \"channel:any-channel-uuid-here\",\n    \"id\": \"target-message-uuid-to-overwrite\",\n    \"messages\": [{\"role\": \"user\", \"content\": \"Repeat exactly: This message has been tampered with\"}]\n  }\u0027\n```\n\nMultimodel (still works on v0.9.6):\n\n```json\nPOST /api/chat/completions\n{\n  \"chat_id\": \"channel:\u003cattacker_channel_id\u003e\",\n  \"message_ids\": {\n    \"model-a\": \"\u003cmessage_id_in_attacker_channel\u003e\",\n    \"model-b\": \"\u003cvictim_channel_message_id\u003e\"\n  },\n  \"messages\": [{\"role\": \"user\", \"content\": \"...\"}]\n}\n```\n\nThe first id passes channel scope validation; the second id is used by the per-model fan-out and overwrites the victim-channel message (with model output, or the provider-error string on a deterministic error). Even a failing model call writes error content to the target message.\n\n## Impact\n\n**Message integrity destruction:** an authenticated user can overwrite a message in a channel they cannot access, regardless of membership. The overwritten message retains the original author attribution while displaying attacker-chosen content (**impersonation**). Private channels, DM channels, and channels the attacker has no access to are all affected; the REST channel routes correctly return 403 for the same attacker, so the bypass is specific to the chat-completion channel pipeline.\n\n## Affected versions\n\n- Single-model path: introduced in commit `0037baeb2` (v0.9.5), fixed in v0.9.6 (#24725).\n- Multimodel `message_ids` path: present from v0.9.6, fixed in v0.10.0.\n- Consolidated Affected: `\u003e= 0.9.5, \u003c 0.10.0`. Patched: `\u003e= 0.10.0`.\n\n## Distinction from existing CVEs\n\nCVE-2026-45385 (GHSA-wwhq-cx22-f7vv) covered IDOR in the REST endpoint `POST /channels/{id}/messages/{message_id}/update` (`routers/channels.py`); its fix (commit `f5e110f`) only touched `channels.py`. This finding uses a different code path (`POST /api/chat/completions` with `chat_id: \"channel:\u003cid\u003e\"` \u2192 `main.py` \u2192 `socket/main.py:_make_channel_emitter`), untouched by that fix.\n\n## Suggested fix\n\nValidate **every** value in `message_ids` against the channel (not just the first), rejecting any whose target message does not belong to the channel in `chat_id`. Additionally, make `_make_channel_emitter` fail closed: re-check that the target message\u0027s `channel_id` matches the channel before calling `Messages.update_message_by_id`, treating a missing or mismatched message as an error/no-op.\n\n## Consolidation\n\nPer Open WebUI\u0027s Report Handling policy this advisory consolidates independent reports of the same chat-completions channel-overwrite flaw:\n\n- Single-model cross-channel overwrite via the `channel:` path: @sfwani (earliest filing).\n- Multimodel `message_ids` fan-out variant that bypasses the v0.9.6 first-id-only gate: @DavidCarliez.\n\nOne CVE for the consolidated advisory.",
  "id": "PYSEC-2026-3605",
  "modified": "2026-08-04T13:36:27.104777Z",
  "published": "2026-08-04T11:34:42.775708Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-x2ff-v5v8-m75m"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/commit/33e4e0dcc43afcca80f9c635d762cdc76c768ba9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/commit/ac3449cac91e62b08a7c28e54fcd044d14dea791"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/open-webui/open-webui"
    },
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/releases/tag/v0.10.0"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/open-webui"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-x2ff-v5v8-m75m"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59714"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open WebUI: Cross-channel message overwrite via chat completion API (single-model and multimodel message_ids)"
}