CVE-2026-22551: @theia/ai chat ui [Eclipse Theia] Data Exfiltration Vulnerability

MODERATE
Advisory Identifier: GHSA-qwjm-9c66-w4q4
CWE-201
Published
Advisory Summary

CVE-2026-22551 is a MODERATE [eclipse theia] data exfiltration vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting @theia/ai chat ui libraries in the npm ecosystem. The issue involves [eclipse theia] data exfiltration via markdown image rendering in ai chat. Remediation is available by upgrading affected packages to version 1.71.0.

CVE-2026-22551 at a Glance

CVE Identifier CVE-2026-22551
GHSA Identifier GHSA-qwjm-9c66-w4q4
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product @theia/ai chat ui
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-22551

To remediate this vulnerability, upgrade all affected @theia/ai chat ui dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@theia/ai-chat-ui fixed: 1.71.0
npm install @theia/ai-chat-ui@1.71.0
@theia/ai-chat fixed: 1.71.0
npm install @theia/ai-chat@1.71.0
@theia/ai-claude-code fixed: 1.71.0
npm install @theia/ai-claude-code@1.71.0
@theia/ai-code-completion fixed: 1.71.0
npm install @theia/ai-code-completion@1.71.0
@theia/ai-core fixed: 1.71.0
npm install @theia/ai-core@1.71.0
@theia/ai-editor fixed: 1.71.0
npm install @theia/ai-editor@1.71.0
@theia/ai-ide fixed: 1.71.0
npm install @theia/ai-ide@1.71.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls @theia/ai-chat-ui

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-22551, inspect your project dependencies using npm:

npm ls @theia/ai-chat-ui

Analyze the terminal output to locate any version of @theia/ai chat ui in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.71.0), your application is affected.

Note: The npm ls @theia/ai-chat-ui command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. In @theia/ai chat ui, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-22551 Affected @theia/ai chat ui Versions

7 component(s)
Fixed Versions:
1.71.0
Product / Package Ecosystem Affected Versions Fixed Version
@theia/ai-chat-ui
npm
< 1.71.0
1.71.0
@theia/ai-chat
npm
< 1.71.0
1.71.0
@theia/ai-claude-code
npm
< 1.71.0
1.71.0
@theia/ai-code-completion
npm
< 1.71.0
1.71.0
@theia/ai-core
npm
< 1.71.0
1.71.0
@theia/ai-editor
npm
< 1.71.0
1.71.0
@theia/ai-ide
npm
< 1.71.0
1.71.0

References

Frequently Asked Questions

What is CVE-2026-22551?
CVE-2026-22551 is a security vulnerability in @theia/ai chat ui involving [Eclipse Theia] Data Exfiltration via Markdown Image Rendering in AI Chat under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which @theia/ai chat ui versions are affected?
Affected versions include releases prior to 1.71.0 across affected packages: @theia/ai-chat-ui, @theia/ai-chat, @theia/ai-claude-code, @theia/ai-code-completion, @theia/ai-core, @theia/ai-editor, @theia/ai-ide.
What version fixes CVE-2026-22551?
Upgrading to 1.71.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @theia/ai-chat-ui affected?
Yes, @theia/ai-chat-ui is affected in releases prior to 1.71.0. Upgrade your dependency to 1.71.0 or later.
Is @theia/ai-chat affected?
Yes, @theia/ai-chat is affected in releases prior to 1.71.0. Upgrade your dependency to 1.71.0 or later.
What CWE is associated with CVE-2026-22551?
CVE-2026-22551 is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check npm dependencies for CVE-2026-22551?
Run the dependency tree command: 'npm ls @theia/ai-chat-ui'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qwjm-9c66-w4q4",
  "modified" : "2026-06-19T19:19:23Z",
  "published" : "2026-06-18T18:35:22Z",
  "aliases" : [ "CVE-2026-22551" ],
  "summary" : "[Eclipse Theia] Data Exfiltration via Markdown Image Rendering in AI Chat",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@theia/ai-chat-ui"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
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      } ]
    } ]
  }, {
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      "name" : "@theia/ai-chat"
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  }, {
    "package" : {
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      "name" : "@theia/ai-claude-code"
    },
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  }, {
    "package" : {
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      "name" : "@theia/ai-core"
    },
    "ranges" : [ {
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  }, {
    "package" : {
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      "name" : "@theia/ai-editor"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.71.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@theia/ai-ide"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.71.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-22551"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/eclipse-theia/theia/issues/16892"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/eclipse-theia/theia/pull/17364"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/eclipse-theia/theia/commit/e3fdfe6992389bc5fa611058d00c39d7408508ed"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/eclipse-theia/theia"
  }, {
    "type" : "WEB",
    "url" : "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/115"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T19:19:22Z",
    "nvd_published_at" : "2026-06-18T16:16:52Z"
  }
}