Vulnerability details

CVE-2026-61826

morpheus65535 bazarr

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

CVSS 3.1
10.0Critical

Official description

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.

CVSS scores

ScoreVersionSourceVector
10.0Critical 3.1 CVEProject cvelistV5 (CNA) (GitHub_M) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

VendorProductVersionsSource
morpheus65535 bazarr < 1.5.7-beta.14 CVEProject cvelistV5 (CNA)

References and advisories

4
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Details

Published
2026-10-30
Last updated
2026-11-05
State
Published
Assigner (CNA)
GitHub_M

Exploit prediction (EPSS)

0.26%
Probability of exploitation in 30 days
18.2%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
None
Technical impact
Total

Weaknesses (CWE)

  • CWE-352
    Cross-Site Request Forgery (CSRF)
  • CWE-862
    Missing Authorization