{"id":"CVE-2026-61891","published":"2026-08-05T12:18:57.310","lastModified":"2026-08-07T15:48:50.607","description":"In Eclipse Theia versions up to and including 1.73.1, the `@theia/filesystem` backend exposes HTTP file-download endpoints (`GET /file`, `GET /files/`, `PUT /files/`) that convert a client-supplied URI directly to a filesystem path and stream the file, without confining it to the workspace or any allow-listed root. In browser (non-Electron) deployments the connection token is enforced only on WebSocket upgrades; the HTTP middleware in `@theia/core` re-issues the cookie and calls `next()` without rejecting tokenless HTTP requests, so these endpoints are reachable without a valid token. As a result an unauthenticated client can read any file readable by the backend process, including files outside the opened workspace (for example `/etc/hosts`, SSH keys, or tokens). Electron mode uses a separate `ElectronSecurityToken` and is not affected via this path.","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwes":["CWE-22","CWE-36","CWE-200","CWE-306"],"vendors":["eclipse"],"products":["theia"],"references":[{"url":"https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4","tags":["Broken Link"]},{"url":"https://gitlab.eclipse.org/security/cve-assignment/-/work_items/176","tags":["Vendor Advisory"]},{"url":"https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/570","tags":["Issue Tracking","Vendor Advisory"]}],"exploitRefs":[{"url":"https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4","tags":["Broken Link"]}],"hasPoc":true,"ai":{"summary":"The flaw allows unauthenticated clients to read any file accessible by the backend process due to improper URI handling and lack of proper token validation in non-Electron deployments.","exploitability":"Exploitation is relatively easy as no valid token is required for HTTP requests, making it a significant security risk.","blast_radius":"If exploited, this could lead to data breaches, unauthorized access to sensitive files, and potential system compromise.","remediation":"Update to the latest version of Eclipse Theia (1.74 or later) which addresses this vulnerability.","tags":["auth-bypass","file-read","web","eclipse"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T06:59:26.142Z"}}