{"id":"CVE-2026-61891","details":"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.","aliases":["GHSA-qqc8-9538-25v4"],"modified":"2026-08-09T03:47:25.317251870Z","published":"2026-08-05T11:03:01.669Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61891.json","cna_assigner":"eclipse","cwe_ids":["CWE-200","CWE-22","CWE-306","CWE-36"]},"references":[{"type":"WEB","url":"https://gitlab.eclipse.org/security/cve-assignment/-/work_items/176"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61891.json"},{"type":"ADVISORY","url":"https://github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-9538-25v4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61891"},{"type":"REPORT","url":"https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/570"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/eclipse-theia/theia","events":[{"introduced":"0"},{"fixed":"172494ea2564ca07690e230805861146007fae79"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.74.0"}]}}],"versions":["v1.73.0","v1.72.0","next","v1.71.0","v1.70.0","v1.69.0","v1.68.0","v1.67.0","v1.66.0","v1.65.0","v1.64.0","v1.63.0","v1.62.0","v1.61.0","v1.60.0","v1.59.0","v1.58.0","v1.57.0","v1.55.0","v1.56.0","v1.54.0","v1.53.0","v1.52.0","v1.50.0","v1.49.0","v1.48.0","v1.47.0","v1.46.0","v1.45.0","v1.44.0","v1.43.0","v1.42.0","v1.41.0","v1.40.0","v1.39.0","v1.38.0","v1.37.0","v1.36.0","v1.35.0","v1.34.0","v1.33.0","v1.32.0","v1.31.0","v1.30.0","v1.29.0","v1.28.0","v1.27.0","v1.26.0","v1.25.0","v1.24.0","v1.23.0","v1.22.1","v1.22.0","v1.21.0","v1.20.0","v1.17.0","v1.16.0","v1.15.0","v1.14.0","v1.13.0","1.13.0","v1.12.0","v1.11.0","v1.10.0","v1.9.0","v1.8.0","v1.7.0","v1.6.0","v1.5.0","v1.4.0","v1.3.0","v1.2.0","v1.1.0","v1.0.0","v0.16.0","v0.15.0","v0.14.0","v0.13.0","v0.12.0","v0.11.0","v0.10.0","v0.9.0","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.4.0","v0.3.19","v0.3.18","v0.3.17","v0.3.16","v0.3.15","v0.3.14","v0.3.13","v0.3.12","v0.3.11","v0.3.10","v0.3.9","v0.3.8","v0.3.4","v0.3.3","v0.3.2","v0.3.1","v0.3.0","v0.2.4","v0.2.3","v0.2.2","v0.2.1","v0.2.0","v0.1.1","v0.1.0","0.0.1-alpha.2","0.0.1-alpha.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61891.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}