🛡️ CVE-2026-46580 — theia

🟠 CVSS 8.8 — High ✅ No Known Exploit CWE-829 NVD
8.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

[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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

CVE-2026-46580 is classified as CWE-829: Inclusion of Functionality from Untrusted Control Sphere. Code is loaded from a source outside the product's control, so that source can change what runs.

Affected software

CVE-2026-46580 is recorded against 7 packages.

  • @theia/ai-chat
  • @theia/ai-chat-ui
  • @theia/ai-claude-code
  • @theia/ai-code-completion
  • @theia/ai-core
  • @theia/ai-editor
  • theia (fixed in 1.71.0)

Timeline and source

Published on 18 June 2026 and last revised on 19 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Package)
gitlab.eclipse.org (Web)

Details

Severity HIGH
CVSS Score 8.8
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE CWE-829
Public Exploit ✅ No
Source NVD
Published 2026-06-18
Updated 2026-08-12
Modified 2026-06-19

Affected Packages

Software From version Fixed in
@theia/ai-chat
@theia/ai-chat-ui
@theia/ai-claude-code
@theia/ai-code-completion
@theia/ai-core
@theia/ai-editor
theia 1.71.0

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