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.

Project Subscriptions

Vendors Products
Sillytavern Subscribe
Sillytavern Subscribe
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-gxx6-h3g6-vwjh SillyTavern has Authentication Bypass via SSO Header Injection
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 02 Jun 2026 02:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 29 May 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Sillytavern
Sillytavern sillytavern
Vendors & Products Sillytavern
Sillytavern sillytavern

Fri, 29 May 2026 18:30:00 +0000

Type Values Removed Values Added
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.
Title SillyTavern: Authentication Bypass via SSO Header Injection
Weaknesses CWE-290
CWE-306
CWE-346
CWE-807
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-02T01:48:37.402Z

Reserved: 2026-05-07T15:30:10.875Z

Link: CVE-2026-44649

cve-icon Vulnrichment

Updated: 2026-06-02T01:48:30.865Z

cve-icon NVD

Status : Deferred

Published: 2026-05-29T19:16:24.720

Modified: 2026-06-02T03:16:17.250

Link: CVE-2026-44649

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-29T19:30:05Z