Eclipse Theia 1.73-1.74 Agent Mode File Path Traversal Arbitrary File Write
CVE-2026-82217 Published on August 31, 2026
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.
Vulnerability Analysis
CVE-2026-82217 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2026-82217. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is a Directory traversal Vulnerability?
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CVE-2026-82217 has been classified to as a Directory traversal vulnerability or weakness.
Products Associated with CVE-2026-82217
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Affected Versions
Eclipse Foundation Eclipse Theia:- Version 1.73.0 and below 1.75.0 is affected.