FKIE_CVE-2026-27707

Vulnerability from fkie_nvd - Published: 2026-02-27 20:21 - Updated: 2026-02-27 20:21
Severity ?
7.3 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Summary
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.
References
security-advisories@github.comhttps://github.com/seerr-team/seerr/commit/4ae20684092b5b28527b23dfbc1a3417858fee8e
security-advisories@github.comhttps://github.com/seerr-team/seerr/releases/tag/v3.1.0
security-advisories@github.comhttps://github.com/seerr-team/seerr/security/advisories/GHSA-rc4w-7m3r-c2f7
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-27707",
  "lastModified": "2026-02-27T20:21:38.760",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-02-27T20:21:38.760",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/seerr-team/seerr/commit/4ae20684092b5b28527b23dfbc1a3417858fee8e"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/seerr-team/seerr/releases/tag/v3.1.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/seerr-team/seerr/security/advisories/GHSA-rc4w-7m3r-c2f7"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-288"
        },
        {
          "lang": "en",
          "value": "CWE-807"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


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