Tautulli has stored XSS in logFile via guest-controlled log_js_errors input

published 2026-06-04 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-34284

cvss: 8.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 1

tautulli tautulli 2.17.1

github.com/Tautulli/Tautulli/releases/tag/v2.17.1 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-06-04)

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/Tautulli/Tautulli/security/advisories/GHSA-f4j7-pjwc-4jrr referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.9	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

Affected products

Tautulli Tautulli

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

CVE List CVE-2026-43984
NVD CVE-2026-43984

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary