SSRF in Sillytavern

CVE-2026-34526

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 version 1.17.0, in src/endpoints/search.js, the hostname is checked against /^\d+\.\d+\.\d+\.\d+$/. This only matches literal dotted-quad IPv4 (e.g. 127.0.0.1, 10.0.0.1). It does not catch: localhost (hostname, not dotted-quad), [::1] (IPv6 loopback), and DNS names resolving to internal addresses (e.g. localtest.me -> 127.0.0.1). A separate port check (urlObj.port !== '') limits exploitation to services on default ports (80/443), making this lower severity than a fully unrestricted SSRF. This issue has been patched in version 1.17.0.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.002 (11.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34526?
CVE-2026-34526 is a medium-severity vulnerability in Sillytavern, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.0/10. Published 2026-04-02.
How severe is CVE-2026-34526?
Medium severity. CVSS v3 base score is 5.0 out of 10.