SillyTavern: SSRF vulnerability in the CORS proxy middleware

published 2026-05-12 5 mo ago modified 2026-07-22 3 mo ago also GHSA-ccfq-2454-f5xw , EUVD-2026-33399

cvss: 6.9; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits: 0; none known

SillyTavern is a locally installed user interface that allows users to interact with text generation large language models, image generation engines, and text-to-speech voice models. Prior to 1.18.0, corsProxyMiddleware forwards req.params.url directly into fetch(url, ...). It only blocks circular requests to its own host and does not enforce destination allowlist or private/loopback restrictions, enabling SSRF. This vulnerability is fixed in 1.18.0.

Patch / fix

fixed in 1 links 1

npm sillytavern 1.18.0

github.com/SillyTavern/SillyTavern/releases/tag/1.18.0 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 5 mo ago (2026-05-29)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

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:N/VA:N/SC:N/SI:N/SA:N
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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 packages

ecosystem	package	affected	fixed in
npm	sillytavern	<1.18.0	1.18.0

Affected products

SillyTavern SillyTavern

Classification

Weakness

CWE-918 Server-Side Request Forgery

References

Sources

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