Vulnerability Description
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 accepts Remote-User (Authelia) and X-Authentik-Username (Authentik) HTTP headers to automatically log in users when SSO is configured. There is no validation that these headers originate from a trusted reverse proxy. Any network client that can reach the SillyTavern port directly can inject these headers and authenticate as any user, including administrators, without a password. This vulnerability is exploitable only when sso.autheliaAuth: true or sso.authentikAuth: true is set in config.yaml (both default to false). This vulnerability is fixed in 1.18.0.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-gxx6-h3g6-vw
- https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-gxx6-h3g6-vw
FAQ
What is CVE-2026-44649?
CVE-2026-44649 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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, ...
How severe is CVE-2026-44649?
CVE-2026-44649 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-44649?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.