CVE-2026-54253: TS3 Manager: Reflected XSS via /api/download port parameter steals operator session
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by GitHub_M, published 2026-09-17).
Weakness: CWE-79: Improper Neutralization of Input During Web Page Generation (‘Cross-site Scripting’)
How it can be exploited
Exploitable over the network with low attack complexity needing no privileges and a user must take an action. Impact: confidentiality high, integrity low, availability none. CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: no. Technical impact: partial.
Public exploit evidence (Exploit Observer)
Also known as: EUVD-2026-82393
VEDAS cluster: VEDAS:DIAMONDCOBRA
Exploit Observer links 3 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (3)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54253.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54253.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54253.rules
Vulnerability databases and vendor advisories (2)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-82393
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-54253
2 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.004
low predicted chance of attack - VEDAS
- 0.986
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- Suricata
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| joni1802 ts3-manager | version < 2.2.6 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
Suricata rules (network detection)
1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-54253 TS3 Manager - Reflected XSS via /api/download port. Add them to your Suricata rule set and reload.
Show the rules
# CVE-2026-54253 - TS3 Manager < 2.2.6 reflected XSS in the /api/download handler
# (packages/server/routes/api.js): the attacker-controlled port query parameter is passed
# to socket.connect() and the resulting error.message is returned via res.send() as
# text/html without CSP. Requires a valid operator session, so request-shape detection only.
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-54253 TS3 Manager - Reflected XSS via /api/download port"; flow:established,to_server; http.uri; content:"/api/download"; nocase; fast_pattern; content:"port="; nocase; pcre:"/[?&]port=[^&]*(?:(?:%3c|<)\s*(?:svg|script|img|iframe|details|body)|on(?:error|load|mouseover|click|focus)\s*(?:=|%3d))/i"; classtype:web-application-attack; reference:cve,CVE-2026-54253; reference:url,https://www.exploit.observer/?keyword=CVE-2026-54253&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=ts3-manager&match=exact; sid:1097802; rev:1;)
CVE-2026-54253.rules on GitHub
References
Other references
- https://github.com/joni1802/ts3-manager/security/advisories/GHSA-3cgm-7p4g-gffj (x_refsource_CONFIRM)
- https://github.com/joni1802/ts3-manager/commit/48df540786d2784c5d7b9bd55786d63e31288d07 (x_refsource_MISC)
- https://github.com/joni1802/ts3-manager/releases/tag/v2.2.6 (x_refsource_MISC)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.