CVE-2026-82217

Directory Traversal Allows Unauthorized File Write in Eclipse Theia's Agent Mode

Published Aug 31, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
In Eclipse Theia versions 1.73.0 up to but not including 1.75.0, the AI "Agent Mode" file-change tools (writeFileContent, suggestFileContent, and the replacement and state helpers) resolved a model-supplied file path without a workspace-containment check. A crafted relative path such as ../.bashrc, an absolute path, or a ~-expanded path could therefore write or delete files outside the workspace with the privileges of the Theia backend OS user. Because the path argument is influenced by model output, it can be steered through indirect prompt injection, and in Agent Mode writes are applied without a confirmation dialog. Writing to a host-executed file such as a shell startup file or ~/.ssh/authorized_keys can escalate to code execution on the backend.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Directory Traversal Allows Unauthorized File Write in Eclipse Theia's Agent Mode
Type Values Removed Values Added
First Time appeared Eclipse
Eclipse eclipse Theia
Vendors & Products Eclipse
Eclipse eclipse Theia
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description In Eclipse Theia versions 1.73.0 up to but not including 1.75.0, the AI "Agent Mode" file-change tools (writeFileContent, suggestFileContent, and the replacement and state helpers) resolved a model-supplied file path without a workspace-containment check. A crafted relative path such as ../.bashrc, an absolute path, or a ~-expanded path could therefore write or delete files outside the workspace with the privileges of the Theia backend OS user. Because the path argument is influenced by model output, it can be steered through indirect prompt injection, and in Agent Mode writes are applied without a confirmation dialog. Writing to a host-executed file such as a shell startup file or ~/.ssh/authorized_keys can escalate to code execution on the backend.
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
eclipse
Published
Updated
Sep 1, 2026, 3:56 AM
Reserved
Aug 28, 2026, 8:47 AM
Status
Deferred
Published
Aug 31, 2026, 2:17 PM
Modified
Sep 1, 2026, 9:11 PM