{"id":"CVE-2026-61891","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-61891","generatedAt":"2026-10-28T09:26:13.856Z","title":"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,…","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.","published":"2026-08-05T12:18:57.000Z","lastModified":"2026-10-24T16:10:00.000Z","status":"Analyzed","sourceIdentifier":"emo@eclipse.org","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-22","CWE-36","CWE-200","CWE-306"],"affected":["eclipse/theia"],"epss":{"score":0.00533,"percentile":0.44839,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4","tags":["Broken Link"],"source":"emo@eclipse.org"},{"url":"https://gitlab.eclipse.org/security/cve-assignment/-/work_items/176","tags":["Vendor Advisory"],"source":"emo@eclipse.org"},{"url":"https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/570","tags":["Issue Tracking","Vendor Advisory"],"source":"emo@eclipse.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-61891","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}