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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-43984

HIGH · 8.9 CVSS v3.1 Published 2026-06-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
93/100
Remediation priority · Urgent
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Versions prior to 2.17.1 expose `log_js_errors` to any authenticated user, including guest users when guest access is enabled. The endpoint writes attacker-controlled strings directly into the main application log. The administrator-only `logFile` view then reads that log file and embeds it into an HTML response without escaping. This creates a stored cross-site scripting condition where a low-privilege guest can inject HTML or JavaScript into the log file and have it execute in an administrator's browser when the log viewer is opened. Version 2.17.1 patches the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Tautulli versions before 2.17.1 allow any authenticated user (including guests) to write attacker-controlled strings to the application log via the unprotected `log_js_errors` endpoint. When administrators view logs through the `logFile` endpoint, these entries are embedded into HTML without escaping, creating a stored XSS that executes in the admin's browser.

MitigationUpgrade Tautulli to version 2.17.1 or later, which patches the vulnerability by adding proper escaping to the log viewer and/or restricting access to the `log_js_errors` endpoint.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Tautulli installation version
    Locate the Tautulli installation and determine the installed version number (typically visible in the application UI header, about page, or configuration files)
    Affected if The installed version is lower than 2.17.1
  2. Verify guest authentication status
    Check whether guest access is enabled in Tautulli authentication settings (usually found in Settings > Authentication or Settings > General > Guest Access)
    Affected if Guest users are permitted to authenticate to the Tautulli application
  3. Confirm log_js_errors endpoint accessibility
    Determine if the /log_js_errors API endpoint is reachable by unauthenticated or guest-level users
    Affected if Guest accounts can reach and submit data to the log_js_errors endpoint
  4. Verify logFile viewing capability
    Confirm that the logFile view functionality exists in the installation and is accessible to administrators
    Affected if Administrators can access a log viewing interface that renders log contents as HTML

A Tautulli installation is affected if it runs a version before 2.17.1 AND has guest authentication enabled, allowing guests to inject malicious JavaScript via the log_js_errors endpoint that will execute when an administrator views the logs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Tautulli to version 2.17.1 or later, which patches the vulnerability by adding proper escaping to the log viewer and/or restricting access to the `log_js_errors` endpoint.

Recommended fix Moderate confidence

2.17.1

  1. 1. Back up your current Tautulli configuration and database before upgrading.
  2. 2. Download Tautulli version 2.17.1 or later from the official GitHub repository.
  3. 3. Stop the Tautulli service.
  4. 4. Replace the existing Tautulli installation files with the new version, preserving your configuration.
  5. 5. Restart the Tautulli service.
  6. 6. Verify the application is running correctly and check that guest access settings remain as intended.
  7. 7. Clear browser cache and test the log viewer functionality as an administrator to confirm the fix is applied.
Caveat No specific breaking changes documented for this point release; standard point releases typically maintain backward compatibility

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-43984 in production — separate from our analysis above.

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