CVE-2026-27707

7.3 HIGH
Published: February 27, 2026 Modified: March 04, 2026
View on NVD

Description

Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Starting in version 2.0.0 and prior to version 3.1.0, an authentication guard logic flaw in `POST /api/v1/auth/jellyfin` allows an unauthenticated attacker to register a new Seerr account on any Plex-configured instance by authenticating with an attacker-controlled Jellyfin server. The attacker receives an authenticated session and can immediately use the application with default permissions, including the ability to submit media requests to Radarr/Sonarr. Any Seerr deployment where all three of the following are true may be vulnerable: `settings.main.mediaServerType` is set to `PLEX` (the most common deployment).; `settings.jellyfin.ip` is set to `""` (default, meaning Jellyfin was never configured); and `settings.main.newPlexLogin` is set to `true` (default). Jellyfin-configured and Emby-configured deployments are not affected. Version 3.1.0 of Seerr fixes this issue.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/seerr-team/seerr/releases/tag/v3.1.0
Source: security-advisories@github.com
Release Notes
https://github.com/seerr-team/seerr/security/advisories/GHSA-rc4w-7m3r-c2f7
Source: security-advisories@github.com
Vendor Advisory Exploit

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.3 / 10.0
EPSS (Exploit Probability)
0.1%
22th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

seerr