{"id":"CVE-2026-44649","aliases":["GHSA-gxx6-h3g6-vwjh"],"url":"https://o3.security/vulnerability/CVE-2026-44649","summary":"SillyTavern: Authentication Bypass via SSO Header Injection","details":"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.","published":"2026-05-29T17:45:26.073Z","modified":"2026-08-07T11:31:01.345438825Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.00218,"percentile":0.12252,"asOf":"2026-08-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"sillytavern","fixedVersion":"1.18.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44649.json"},{"type":"ADVISORY","url":"https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-gxx6-h3g6-vwjh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44649"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:01.345438825Z"}}