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Fencer Intel
high 8.2

CVE-2026-54253 json

TS3 Manager: Reflected XSS via /api/download port parameter steals operator session

published 5mo ago modified last mo. also EUVD-2026-82393 , GHSA-3cgm-7p4g-gffj

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository joni1802/ts3-manager. 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
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

TS3 Manager is modern web interface for maintaining Teamspeak3 servers. Prior to 2.2.6, the /api/download handler in packages/server/routes/api.js passes the attacker-controlled port query parameter to socket.connect(port, host) and returns the resulting error.message through res.status(400).send(error.message) as text/html without a Content Security Policy. When a logged-in operator follows a crafted top-level link, the reflected value executes in the manager origin. The token cookie set in packages/ui/src/store/modules/query.js lacks HttpOnly, Secure, and an explicit SameSite attribute, allowing the script to read the token and call the autofillform event in packages/server/socket.js. autofillform returns the decoded JWT, including the cleartext ServerQuery password, enabling operator-session hijacking and control of the managed TeamSpeak server when the operator uses administrative ServerQuery credentials. A valid operator session and user interaction are required. This issue is fixed in 2.2.6.

Patch / fix

  • joni1802 ts3_manager 2.2.6

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CISA SSVC

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

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/joni1802/ts3-manager/security/advisories/GHSA-3cgm-7p4g-gffj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Affected products

  • joni1802 ts3-manager

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 joni1802/ts3-manager 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.