CVE intelligence and bounded remediation

CVE-2026-43986 — Tautulli is a Python based monitoring and tracking tool for Plex Media Server

Critical CVSS 9.9

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.

Severity
Critical
CVSS
9.9 (3.1)
Published
2026-06-04
CISA KEV
Not currently listed
Ecosystem
python/pypi
Weaknesses
CWE-918

Affected products

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Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

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