{"id":"GHSA-525j-2hrj-m8fp","summary":"SillyTavern: Path Traversal allows file existence oracle","details":"### Summary\n\nA path traversal vulnerability in the static file route handler allows any unauthenticated user to determine whether files exist anywhere on the server's filesystem. By sending percent-encoded `../` sequences (`%2E%2E%2F`) in requests to static file routes, an attacker can check for the existence of files (404 if it doesn't exist, 403 means it exists).\n\n### Details\n\nThe vulnerability is in `createRouteHandler` (`src/users.js:947–963`), which backs all user-data static file routes:\n\n```javascript\nfunction createRouteHandler(directoryFn) {\n    return async (req, res) =\u003e {\n        const directory = directoryFn(req);\n        const filePath = decodeURIComponent(req.params[0]);\n        const exists = fs.existsSync(path.join(directory, filePath)); // no boundary check here\n        if (!exists) {\n            return res.sendStatus(404);\n        }\n        return res.sendFile(filePath, { root: directory });\n    };\n}\n```\n\n`req.params[0]` contains the raw (percent-encoded) wildcard from the URL. After `decodeURIComponent`, a request path like `/characters/%2E%2E%2F%2E%2E%2FUsers/kirakira` decodes to `../../Users/kirakira`, and `path.join` resolves it outside the intended directory. `res.sendFile` correctly blocks the file from being served (the `send` module's root check returns 403), but `fs.existsSync` had already run, and the 403/404 distinction reveals the result.\n\nAffected routes (they all use the same handler, so they're all affected):\n\n- `/characters/*`\n- `/user/files/*`\n- `/assets/*`\n- `/user/images/*`\n- `/backgrounds/*`\n- `/User%20Avatars/*`\n\n### PoC\n\n```bash\ncurl -o /dev/null -s -w \"%{http_code}\\n\" \"http://localhost:8000/characters/%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2FUsers/kirakira/something\"\n```\n\n### Impact\n\nWhile file contents cannot be read (the `send` module blocks actual delivery), anyone who can reach the SillyTavern HTTP port can check the existence of files on the host filesystem.\n\n### Resolution\n\nThe issue was addressed in version 1.17.0.","aliases":["CVE-2026-34523"],"modified":"2026-04-06T17:31:29.470446Z","published":"2026-04-01T21:40:22Z","database_specific":{"cwe_ids":["CWE-22"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-04-01T21:40:22Z","nvd_published_at":"2026-04-02T18:16:29Z"},"references":[{"type":"WEB","url":"https://github.com/SillyTavern/SillyTavern/security/advisories/GHSA-525j-2hrj-m8fp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34523"},{"type":"PACKAGE","url":"https://github.com/SillyTavern/SillyTavern"},{"type":"WEB","url":"https://github.com/SillyTavern/SillyTavern/releases/tag/1.17.0"}],"affected":[{"package":{"name":"sillytavern","ecosystem":"npm","purl":"pkg:npm/sillytavern"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.17.0"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 1.16.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-525j-2hrj-m8fp/GHSA-525j-2hrj-m8fp.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}