CVE-2026-30975
Received Received - Intake
Authentication Bypass in Sonarr Affects Local Access Without Proxy

Publication date: 2026-03-25

Last updated on: 2026-03-30

Assigner: GitHub, Inc.

Description
Sonarr is a PVR for Usenet and BitTorrent users. Versions prior to 4.0.16.2942 have an authentication bypass that affected users that had disabled authentication for local addresses (Authentication Required set to: `Disabled for Local Addresses`) without a reverse proxy running in front of Sonarr that didn't not pass through the invalid header. Patches are available in version 4.0.16.2942 in the nightly/develop branch and version 4.0.16.2944 for stable/main releases. Some workarounds are available. Make sure Sonarr's Authentication Required setting is set to `Enabled`, run Sonarr behind a reverse proxy, and/or do not expose Sonarr directly to the internet and instead rely on accessing it through a VPN, Tailscale or a similar solution.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-03-25
Last Modified
2026-03-30
Generated
2026-06-16
AI Q&A
2026-03-26
EPSS Evaluated
2026-06-15
NVD
CVE-2026-30975
EUVD
EUVD-2026-15990
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
sonarr sonarr to 4.0.16.2942 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-290 This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

CVE-2026-30975 is an authentication bypass vulnerability in Sonarr versions prior to 4.0.16.2942.

The issue occurs when users disable authentication for local addresses (setting "Authentication Required" to Disabled for Local Addresses) without running Sonarr behind a properly configured reverse proxy that correctly handles the X-Forwarded-For header.

This misconfiguration allows attackers to bypass authentication remotely without any privileges or user interaction.

The vulnerability is classified under CWE-290 (Authentication Bypass by Spoofing).

Mitigation Strategies

To mitigate the authentication bypass vulnerability in Sonarr versions prior to 4.0.16.2942, you should take the following immediate steps:

  • Enable the "Authentication Required" setting in Sonarr instead of disabling it for local addresses.
  • Run Sonarr behind a reverse proxy that is properly configured to handle the X-Forwarded-For header correctly.
  • Avoid exposing Sonarr directly to the internet; instead, access it through a VPN, Tailscale, or a similar secure access solution.
  • Update Sonarr to version 4.0.16.2942 (nightly/develop) or 4.0.16.2944 (stable/main) where the vulnerability is patched.
Impact Analysis

This vulnerability can lead to high confidentiality and integrity impacts because attackers can bypass authentication and gain unauthorized access to Sonarr.

Attackers do not need any privileges or user interaction to exploit this vulnerability.

However, availability is not affected by this vulnerability.

Exploitation could allow attackers to view or modify sensitive data managed by Sonarr.

Compliance Impact

The authentication bypass vulnerability in Sonarr allows unauthorized remote access when authentication is disabled for local addresses without a properly configured reverse proxy. This leads to high confidentiality and integrity impacts, which could result in unauthorized access to sensitive data.

Such unauthorized access risks violating data protection standards and regulations like GDPR and HIPAA, which require strict access controls and protection of personal and sensitive information.

Therefore, if this vulnerability is exploited, it could lead to non-compliance with these regulations due to potential data breaches or unauthorized data manipulation.

Mitigations such as enabling authentication, using a correctly configured reverse proxy, or restricting access via VPNs are essential to maintain compliance.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-30975. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart