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.
Affected products
eclipse: theia
References3
- gitlab.eclipse.org/security/cve-assignment/-/work_items/176 Vendor Advisory
- gitlab.eclipse.org/security/vulnerability-reports/-/issues/570 Issue TrackingVendor Advisory
- github.com/eclipse-theia/theia/security/advisories/GHSA-qqc8-95… Broken Link
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 1% percentile: 46 · as of 13 November 2026
- CWE
- CWE-22CWE-36CWE-200CWE-306
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