[Eclipse Theia] Indirect Prompt Injection via Adversarial Workspace File and Directory Names in AI Chat

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.4 · 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 · score source

EPSS

• CVE-2026-44688: 0.51% estimated exploitation activity in the next 30 days; percentile 43.33 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

In Eclipse Theia versions prior to 1.71.0, the AI chat agent processed workspace file and directory names as part of its prompt context without distinguishing them from system instructions. An attacker could craft a malicious repository with adversarial directory or file names that, when analyzed by the AI agent, would cause the agent to follow attacker-controlled instructions (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.

Published by the source

18 Jun 2026, 18:35 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 12:56 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3jww-hxqj-wfq2

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-3jww-hxqj-wfq2

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# Patch Next advisory brief: CVE-2026-44688

Advisory: [Eclipse Theia] Indirect Prompt Injection via Adversarial Workspace File and Directory Names in AI Chat
IDs: CVE-2026-44688, GHSA-3jww-hxqj-wfq2
Record: https://patchnext.com/advisories/cve-2026-44688 (revision 3, source checked 26 Oct 2026, 12:56 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @theia/ai-code-completion 1.71.0; @theia/ai-claude-code 1.71.0; @theia/ai-chat-ui 1.71.0; @theia/ai-core 1.71.0; @theia/ai-editor 1.71.0; @theia/ai-chat 1.71.0; @theia/ai-ide 1.71.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @theia/ai-code-completion: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-claude-code: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-chat-ui: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-core: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-editor: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-chat: affected < 1.71.0; fixed in 1.71.0
- npm @theia/ai-ide: affected < 1.71.0; fixed in 1.71.0

## Suggested inspection (read-only)
- `npm ls @theia/ai-code-completion --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-claude-code --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-chat-ui --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-core --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-editor --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-chat --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @theia/ai-ide --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @theia/ai-code-completion, @theia/ai-claude-code, @theia/ai-chat-ui, @theia/ai-core, @theia/ai-editor, @theia/ai-chat, @theia/ai-ide.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-3jww-hxqj-wfq2 (OSV record GHSA-3jww-hxqj-wfq2 lists affected ranges: npm @theia/ai-chat-ui >=0 =0 =0 =0 =0 =0 =0 <1.71.0 (fixed))
- Verified: https://github.com/advisories/GHSA-3jww-hxqj-wfq2 (GitHub-reviewed advisory GHSA-3jww-hxqj-wfq2 lists affected ranges: npm @theia/ai-chat-ui >=0 =0 =0 =0 =0 =0 =0 <1.71.0)

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