CVE-2026-43986 — CRITICAL (9.9)

Vulnerability Description

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose a public `/image/<hash>` route that resolves attacker-controlled entries from `image_hash_lookup` and replays them through the same server-side image fetch logic used by authenticated image proxying. A low-privilege guest user can seed a malicious external image URL into this lookup table and then trigger server-side fetches through a fully unauthenticated endpoint. This turns an authenticated SSRF primitive into a persistent unauthenticated SSRF gadget. Once the malicious hash entry exists, any external user can request `/image/<hash>.png` and cause the PMS or Tautulli host to fetch an arbitrary attacker-chosen URL. Version 2.17.1 patches the issue.

CVSS Score

9.9

CRITICAL

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

LOW

Related Weaknesses (CWE)

CWE-918

References

FAQ

What is CVE-2026-43986?

CVE-2026-43986 is a vulnerability with a CVSS score of 9.9 (CRITICAL). Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose a public `/image/<hash>` route that resolves attacker-controlled entries from `image_hash...

How severe is CVE-2026-43986?

CVE-2026-43986 has been rated CRITICAL with a CVSS base score of 9.9/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-43986?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.