CVE-2026-22551 [Eclipse Theia] Data Exfiltration via Markdown Image Rendering in AI Chat
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-22551?
CVE-2026-22551 is a medium-severity vulnerability in Eclipse Theia, published on 18 Jun 2026.
Official description
In Eclipse Theia versions prior to 1.71.0, the AI chat rendered Markdown image tags from AI responses, triggering HTTP requests to arbitrary external URLs without restriction. Combined with prompt injection in a malicious workspace, an attacker could induce the AI agent to construct image URLs encoding sensitive information from the workspace or conversation context, exfiltrating it to attacker-controlled servers. The workspace trust enforcement introduced in v1.71.0 mitigates the documented attack chain by disabling AI features in untrusted workspaces.
Which versions are affected by CVE-2026-22551?
14 open source packages ship an affected version, including @theia/ai-chat, @theia/ai-chat-ui and @theia/ai-claude-code. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@theia/ai-chat npm | All versions | 1.71.0 |
@theia/ai-chat npm | All versions | 1.71.0 |
@theia/ai-chat-ui npm | All versions | 1.71.0 |
@theia/ai-chat-ui npm | All versions | 1.71.0 |
@theia/ai-claude-code npm | All versions | 1.71.0 |
@theia/ai-claude-code npm | All versions | 1.71.0 |
8 more packages
@theia/ai-code-completion npm | All versions | 1.71.0 |
@theia/ai-code-completion npm | All versions | 1.71.0 |
@theia/ai-core npm | All versions | 1.71.0 |
@theia/ai-core npm | All versions | 1.71.0 |
@theia/ai-editor npm | All versions | 1.71.0 |
@theia/ai-editor npm | All versions | 1.71.0 |
@theia/ai-ide npm | All versions | 1.71.0 |
@theia/ai-ide npm | All versions | 1.71.0 |
Products include Eclipse Theia.
How do I fix CVE-2026-22551?
Upgrade @theia/ai-chat to 1.71.0 or later.
Is CVE-2026-22551 being exploited?
There is no known exploitation of CVE-2026-22551 in the wild and no public exploit code.
Other vulnerabilities in Eclipse Theia
- CVE-2021-34436 XML external entity in Eclipse Theia
- CVE-2020-27224 Cross-site Scripting (XSS) in Eclipse Theia
- CVE-2026-60009 File upload in Eclipse Theia
- CVE-2021-34435 Remote code execution in Eclipse Theia
- CVE-2026-44688 [Eclipse Theia] Indirect Prompt Injection via Adversarial Workspace File and Directory Names in AI Chat
Sources
Also known as GHSA-qwjm-9c66-w4q4, UBUNTU-CVE-2026-22551.