CVE-2026-43985: Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose `configUpdate` as a state-changing admi...

Description

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose `configUpdate` as a state-changing administrator endpoint, but the route does not enforce `POST` and does not use any anti-CSRF token. In the default form and JWT-based authentication mode, the administrator session cookie is issued with `SameSite=Lax`, which still permits top-level cross-site navigation requests. An attacker can exploit this by luring a logged-in administrator to a malicious page that submits a cross-site request to `/configUpdate` and overwrites the local administrator username and password. The attacker can then sign in directly with the chosen credentials and take over the Tautulli administrative interface. Version 2.17.1 patches the issue.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.15%

4.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-352

References

Timeline

Published: Jun 4, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-43985?

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose `configUpdate` as a state-changing administrator endpoint, but the route does not enforce `POST` and does not use any anti-CSRF token. In the default form and JWT-based authentication mode, the administrator session cookie is issued with `SameSite=Lax`, which still permits top-level cross-site navigation requests. An attacker can exploit this by luring a logged-in administrator to a malicious page that submits a cross-site request to `/configUpdate` and overwrites the local administrator username and password. The attacker can then sign in directly with the chosen credentials and take over the Tautulli administrative interface. Version 2.17.1 patches the issue.

How severe is CVE-2026-43985?

CVE-2026-43985 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2026-43985?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.