CVE-2026-34526: SSRF in SillyTavern AI

The SSRF vulnerability in SillyTavern AI arises from insufficient validation of hostnames in the search.js endpoint. The current validation only allows literal IPv4 dotted-quad addresses, failing to block hostnames like localhost, IPv6 loopback addresses ([::1]), or DNS names resolving to internal IPs (e.g., localtest.me). Successful exploitation could enable an attacker to trigger requests to internal services, potentially exposing sensitive data or gaining unauthorized access to internal systems. While the port check limits exploitation to default ports (80/443), the potential for internal reconnaissance and access to vulnerable internal services remains a significant risk.

1. Reserved2026-03-30
2. Published2026-04-01
3. Modified2026-04-06
4. EPSS updated2026-04-10

The primary mitigation for CVE-2026-34526 is to upgrade SillyTavern AI to version 1.17.0 or later, which includes the necessary hostname validation fixes. If upgrading is not immediately feasible, consider implementing a Web Application Firewall (WAF) or reverse proxy with strict hostname filtering rules to block requests to potentially malicious internal addresses. Monitor SillyTavern AI logs for unusual outbound requests, particularly those targeting internal IP addresses or hostnames. Restrict network access to SillyTavern AI to only authorized users and systems.