[Eclipse Theia] Indirect Prompt Injection via Auto-Loaded Workspace Prompt Template Files in AI Chat
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 software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @theia/ai-chat | < 1.71.0 | 1.71.0 |
| npm package | @theia/ai-chat-ui | < 1.71.0 | 1.71.0 |
| npm package | @theia/ai-claude-code | < 1.71.0 | 1.71.0 |
| npm package | @theia/ai-code-completion | < 1.71.0 | 1.71.0 |
| npm package | @theia/ai-core | < 1.71.0 | 1.71.0 |
| npm package | @theia/ai-editor | < 1.71.0 | 1.71.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-46580
- https://github.com/eclipse-theia/theia/issues/16892
- https://github.com/eclipse-theia/theia/pull/17364
- https://github.com/eclipse-theia/theia/commit/e3fdfe6992389bc5fa611058d00c39d7408508ed
- https://github.com/eclipse-theia/theia
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/114
- CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-829- Platform
- npm
- Package
@theia/ai-chat, @theia/ai-chat-ui, @theia/ai-claude-code- Disclosed
- 18.06.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-m973-pr9r-hp2w - CC BY 4.0
Vulnerability history: @theia/ai-code-completion
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 06.2026 06.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
- Medium 1
Disclosures per year
- 2026: 3
-
[Eclipse Theia] Indirect Prompt Injection via Auto-Loaded Workspace Prompt Template Files in AI Chat this entry
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