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, SillyTavern exposes /api/search/searxng, which accepts attacker-controlled baseUrl and uses it directly to build outbound server-side fetches. An authenticated low-privilege user can point baseUrl at an internal or loopback HTTP service and receive the /search response body. This vulnerability is fixed in 1.18.0.

Affected: npm: sillytavern

## Resolution

SillyTavern 1.18.0 added a generic server-side request filter (Private Request Whitelisting). Since we expect users to use the application in a trusted environment, the filter is disabled by default, however it is strongly advised to be enabled and properly configured when an instance is being hosted over a network, as suggested by a console warning message and an officially published security checklist for administrators.

Documentation:

- https://docs.sillytavern.app/administration/config-yaml/#private-address-whitelisting - https://docs.sillytavern.app/administration/#security-checklist

## Note on future SSRF findings

Since the request filter applies to the entire application, no SSRF vulnerabilities against individual endpoints will be accepted, unless it has been proven that a properly configured and enabled filter can be bypassed in an undocumented way. Only advisories disclosed before the 1.18.0 release will be posted if their concern is SSRF.

## Summary SillyTavern 1.17.0 exposes `/api/search/searxng`, which accepts attacker-controlled `baseUrl` and uses it directly to build outbound server-side fetches. An authenticated low-privilege user can point `baseUrl` at an internal or loopback HTTP service and receive the `/search` response body.

Confirmed version: SillyTavern 1.17.0 from the audited source tree. Broader affected versions and patched versions should be confirmed by the maintainer.

## Details The `/api/search/searxng` route in `src/endpo…