Vulnerability in Sonarr
CVE-2026-30975
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.006 (46.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Sonarr — versions < 4.0.16.2942
Weakness classification (CWE)
References
- github.com/Sonarr/Sonarr/security/advisories/GHSA-h5qx-5hjf-7c9r (Vendor Advisory)
- github.com/Sonarr/Sonarr/releases/tag/v4.0.16.2942 (Release Notes)
- github.com/Sonarr/Sonarr/releases/tag/v4.0.16.2944 (Release Notes)
Frequently asked questions
- What is CVE-2026-30975?
- CVE-2026-30975 is a high-severity vulnerability in Sonarr, classified under Authentication Bypass by Spoofing. CVSS score: 8.1/10. Published 2026-03-25.
- How severe is CVE-2026-30975?
- High severity. CVSS v3 base score is 8.1 out of 10.