Bazarr: Plex OAuth API namespace is entirely unauthenticated, allowing config tampering, integration takeover and server-side request forgery

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-61826",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-10-30T17:12:43.384Z",
    "dateReserved": "2026-07-10T20:17:57.993Z",
    "datePublished": "2026-10-30T17:12:43.384Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M",
        "dateUpdated": "2026-10-30T17:12:43.384Z"
      },
      "title": "Bazarr: Plex OAuth API namespace is entirely unauthenticated, allowing config tampering, integration takeover and server-side request forgery",
      "descriptions": [
        {
          "lang": "en",
          "value": "Bazarr is a companion application to Sonarr and Radarr. Prior to 1.5.7-beta.14, the `api_ns_plex` namespace in `bazarr/api/plex/oauth.py` omits `@authenticate` on its Resource handlers, while normal APIs require an API key and no global authentication hook compensates. Anonymous callers can invoke `POST /api/plex/oauth/logout` to clear credentials and disable the integration, or `POST /api/plex/apikey` to persist an attacker-selected key, without a PIN, account or state precondition. `POST /api/plex/oauth/pin` and `GET /api/plex/oauth/pin/<pin_id>/check` additionally allow an attacker who completes a PIN with an attacker-controlled Plex account to bind that account's token to the instance. `PlexPinCheck` skips state validation when `state_param` is absent and merely logs a mismatch without stopping execution. `POST /api/plex/select-server`, `POST /api/plex/oauth/servers`, `POST /api/plex/webhook/create`, `POST /api/plex/webhook/delete` and `POST /api/plex/encrypt-apikey` expose further `write_config()` operations. Attacker-controlled server URLs feed later outbound requests carrying the configured API key in `X-Plex-Token`, enabling server-side request forgery and credential exposure in addition to persistent configuration tampering and integration denial of service. Version 1.5.7-beta.14 closes the anonymous API-mutation path by adding authentication; complete OAuth state validation is not established and remains a separate residual for curator review."
        }
      ],
      "affected": [
        {
          "vendor": "morpheus65535",
          "product": "bazarr",
          "versions": [
            {
              "version": "< 1.5.7-beta.14",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-352: Cross-Site Request Forgery (CSRF)",
              "cweId": "CWE-352",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-862: Missing Authorization",
              "cweId": "CWE-862",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4",
          "name": "https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4",
          "tags": [
            "x_refsource_CONFIRM"
          ]
        },
        {
          "url": "https://github.com/morpheus65535/bazarr/commit/4bd29252feebd0803e84cc3ce1bdd24c3a076ed4",
          "name": "https://github.com/morpheus65535/bazarr/commit/4bd29252feebd0803e84cc3ce1bdd24c3a076ed4",
          "tags": [
            "x_refsource_MISC"
          ]
        },
        {
          "url": "https://github.com/morpheus65535/bazarr/commit/f9a8a9514944be0e7b826e67cde042cebfe9c97e",
          "name": "https://github.com/morpheus65535/bazarr/commit/f9a8a9514944be0e7b826e67cde042cebfe9c97e",
          "tags": [
            "x_refsource_MISC"
          ]
        },
        {
          "url": "https://github.com/morpheus65535/bazarr/tree/v1.5.7-beta.14",
          "name": "https://github.com/morpheus65535/bazarr/tree/v1.5.7-beta.14",
          "tags": [
            "x_refsource_MISC"
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
            "attackVector": "NETWORK",
            "attackComplexity": "LOW",
            "privilegesRequired": "NONE",
            "userInteraction": "NONE",
            "scope": "CHANGED",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "availabilityImpact": "HIGH",
            "baseScore": 10,
            "baseSeverity": "CRITICAL"
          }
        }
      ]
    }
  }
}