# CVE-2026-30975: Sonarr Authentication Bypass vulnerability

> Attackers can bypass authentication in Sonarr when local authentication is disabled and no reverse proxy filters headers, allowing unauthorized access.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 25 Mar 2026
- **Updated:** 26 Mar 2026
- **Also known as:** GHSA-h5qx-5hjf-7c9r

## What is CVE-2026-30975?

CVE-2026-30975 is a high-severity authentication bypass vulnerability in Sonarr, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-30975?

It affects 1 product.


Products: Sonarr Sonarr.

## How do I fix CVE-2026-30975?

No fix has been published for CVE-2026-30975 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-30975 being exploited?

There is no known exploitation of CVE-2026-30975 in the wild and no public exploit code.

## Other vulnerabilities in Sonarr

- [CVE-2026-30976](https://insights.sbomify.com/CVE-2026-30976/): Sonarr Path Traversal vulnerability (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30975 and fix it if it is affected.

What it is: CVE-2026-30975 is a high-severity authentication bypass vulnerability in Sonarr, published on 25 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-30975 in the wild and no public exploit code.

Affected product: Sonarr. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-30975/ (Markdown: https://insights.sbomify.com/CVE-2026-30975/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30975
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30975
- OSV: https://osv.dev/vulnerability/CVE-2026-30975

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30975/
Summaries are generated and may contain mistakes; the official description above is the record.