---
id: CVE-2026-46580
title: >-
  [Eclipse Theia] Indirect Prompt Injection via Auto-Loaded Workspace Prompt
  Template Files in AI Chat
summary: >-
  [Eclipse Theia] Indirect Prompt Injection via Auto-Loaded Workspace Prompt
  Template Files in AI Chat
severity: high
cwe:
  - CWE-829
vendor: theia
product: '@theia/ai-chat-ui'
ecosystem: npm
affected:
  - '@theia/ai-chat-ui < 1.71.0'
  - '@theia/ai-chat < 1.71.0'
  - '@theia/ai-claude-code < 1.71.0'
  - '@theia/ai-code-completion < 1.71.0'
  - '@theia/ai-core < 1.71.0'
  - '@theia/ai-editor < 1.71.0'
patched:
  - '@theia/ai-chat-ui 1.71.0'
  - '@theia/ai-chat 1.71.0'
  - '@theia/ai-claude-code 1.71.0'
  - '@theia/ai-code-completion 1.71.0'
  - '@theia/ai-core 1.71.0'
  - '@theia/ai-editor 1.71.0'
published: '2026-06-18'
updated: '2026-06-19'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-m973-pr9r-hp2w'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46580'
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/114'
  - url: 'https://github.com/eclipse-theia/theia/issues/16892'
  - url: 'https://github.com/eclipse-theia/theia/pull/17364'
  - url: >-
      https://github.com/eclipse-theia/theia/commit/e3fdfe6992389bc5fa611058d00c39d7408508ed
  - url: 'https://github.com/advisories/GHSA-m973-pr9r-hp2w'
tags:
  - ghsa
  - npm
epss: 0.00507
epssPercentile: 0.40655
ingestedAt: '2026-06-29T13:24:35.695Z'
---

## Overview

In Eclipse Theia versions prior to 1.71.0, files matching the pattern .prompts/*.prompttemplate in a workspace were automatically loaded and could override or extend the AI agent's system prompts. An attacker could craft a malicious repository containing prompt template files that, when the workspace was opened in Theia, replaced the AI's system instructions with attacker-controlled content (indirect prompt injection). Combined with other AI chat features available in untrusted workspaces, this enabled attack chains leading to data exfiltration via Markdown image rendering or arbitrary command execution via task definitions.

## Affected packages

- `@theia/ai-chat-ui < 1.71.0`
- `@theia/ai-chat < 1.71.0`
- `@theia/ai-claude-code < 1.71.0`
- `@theia/ai-code-completion < 1.71.0`
- `@theia/ai-core < 1.71.0`
- `@theia/ai-editor < 1.71.0`

## Remediation

Upgrade to a patched release:

- `@theia/ai-chat-ui 1.71.0`
- `@theia/ai-chat 1.71.0`
- `@theia/ai-claude-code 1.71.0`
- `@theia/ai-code-completion 1.71.0`
- `@theia/ai-core 1.71.0`
- `@theia/ai-editor 1.71.0`