JoeCastrom mcp-chat-studio LLM Models API llm.js server-side request forgery

published 2026-04-27 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-25906

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

A vulnerability was detected in JoeCastrom mcp-chat-studio up to 1.5.0. Affected by this issue is some unknown functionality of the file server/routes/llm.js of the component LLM Models API. Performing a manipulation of the argument req.query.base_url results in server-side request forgery. Remote exploitation of the attack is possible. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 6 mo ago (2026-04-27)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/JoeCastrom/mcp-chat-studio/issues/4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	3.0	7.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R
CNA	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	5.5	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

JoeCastrom mcp-chat-studio

Classification

Weakness

CWE-918 Server-Side Request Forgery

References

github.com /JoeCastrom/mcp-chat-studio/issues/4
exploit, issue-tracking
vuldb.com /vuln/359746
vdb-entry, technical-description
vuldb.com /vuln/359746/cti
signature, permissions-required
vuldb.com /submit/801896
third-party-advisory
github.com /JoeCastrom/mcp-chat-studio/
product

Sources

CVE List CVE-2026-7147
NVD CVE-2026-7147

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.

Summary