The flaw allows an attacker to send requests to internal network addresses through the /api/search/visit endpoint because the hostname check only permits dotted‑quad IPs. Hostnames such as localhost, IPv6 loopback [::1], and DNS names that resolve to internal IPs are not blocked, enabling SSRF. The vulnerability is limited to services that listen on default ports (80 and 443), which reduces its severity compared with a fully unrestricted SSRF.

All installations of SillyTavern older than version 1.17.0 are affected. The application is open‑source and runs locally; the attack surface is the /api/search/visit endpoint in src/endpoints/search.js.

The CVSS base score of 5 indicates medium severity, and the EPSS score of less than 1 % shows a low probability of exploitation in the wild. The vulnerability is not listed in CISA’s KEV catalog. Exploitation requires sending a request to the vulnerable endpoint, either from an authenticated or unauthenticated user if the API is publicly accessible, and the attacker must know at least a valid default port to leverage the fallback port check.