CVE-2026-82217

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-31 · updated 2026-09-01
Weakness: CWE-22

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.

Affected products

Eclipse Foundation Eclipse Theia: from 1.73.0 before 1.75.0 — fixed in 1.75.0

How to fix

Upgrade to a fixed version: Eclipse Foundation Eclipse Theia 1.75.0. Check the vendor advisory for mitigations.

References

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