In Eclipse Theia versions 1.66.0 and up until including 1.73.1, the `@theia/plugin-ext` backend exposes the `/hostedPlugin/:pluginId/:path(*)` HTTP endpoint, which resolves the requested file path with `path.resolve(localPath, filePath)` without verifying that the resolved path stays within the plugin's directory. An unauthenticated network attacker can send percent-encoded `../` sequences (`%2e%2e%2f`) that decode into the path parameter and escape the plugin directory, allowing arbitrary files readable by the Theia backend process to be retrieved. Plugin IDs are derived deterministically from a plugin's publisher and name, so built-in plugins serve as reliable anchors that require no prior knowledge of the target system.
References
| Link | Resource |
|---|---|
| https://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48 | Broken Link |
| https://gitlab.eclipse.org/security/cve-assignment/-/work_items/133 | Vendor Advisory |
| https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524 | Issue Tracking Mitigation Vendor Advisory |
Configurations
History
07 Aug 2026, 20:23
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Eclipse theia
Eclipse |
|
| References | () https://github.com/eclipse-theia/theia/security/advisories/GHSA-qmm6-p8q4-2g48 - Broken Link | |
| References | () https://gitlab.eclipse.org/security/cve-assignment/-/work_items/133 - Vendor Advisory | |
| References | () https://gitlab.eclipse.org/security/vulnerability-reports/-/issues/524 - Issue Tracking, Mitigation, Vendor Advisory | |
| CPE | cpe:2.3:a:eclipse:theia:*:*:*:*:*:*:*:* |
05 Aug 2026, 11:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-08-05 11:16
Updated : 2026-08-07 20:23
NVD link : CVE-2026-12609
Mitre link : CVE-2026-12609
CVE.ORG link : CVE-2026-12609
JSON object : View
Products Affected
eclipse
- theia
CWE
CWE-22
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')