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Fencer Intel
medium 4.8

CVE-2026-49995 json

Tautulli: Stored Cross-Site Scripting (XSS) in the newsletter

published 4mo ago modified last mo. also EUVD-2026-84069 , GHSA-r6pg-vqxj-v75j

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository Tautulli/Tautulli. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
4.8
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to 2.17.2, the newsletter cron field stored in the newsletters table is inserted by data/interfaces/default/newsletter_config.html into a JavaScript string without safe JSON encoding. An administrator or caller with the Tautulli API key can store a crafted cron value, and an administrator who later opens the newsletter configuration modal passively triggers script execution in the Tautulli web context. The stored value persists in the database and can continue to execute after credential rotation until it is removed. This issue is fixed in version 2.17.2.

Patch / fix

Is CVE-2026-49995 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/Tautulli/Tautulli/security/advisories/GHSA-r6pg-vqxj-v75j referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 4.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CNA 4.0 4.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Tautulli Tautulli

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel 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.

The maintainers of Tautulli/Tautulli published their own advisory on GitHub. Reviewed sources take precedence over it.

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