CVE-2026-53957
Contentful MCP Server: export_space/import_space tools pass LLM-controlled `host`/`proxy` args to CMA client, redirecting server PAT to attacker-controlled endpoint
- State
- Published
- Severity
- 7.7 High
- Published
- Sep 15, 2026
- Updated
- Sep 17, 2026
- Reserved
- Jun 11, 2026
Description
Contentful MCP Server is a Model Context Protocol server for the Contentful Management API. Prior to @contentful/mcp-server 1.7.19 and @contentful/mcp-tools 0.4.5, export_space and import_space in packages/mcp-tools/src/tools/jobs/space-to-space-migration/exportSpace.ts and packages/mcp-tools/src/tools/jobs/space-to-space-migration/importSpace.ts expose host, proxy, rawProxy, and insecure network options to LLM-controlled tool arguments and combine those options with the server's CONTENTFUL_MANAGEMENT_TOKEN. After space_to_space_migration_handler enables the migration tools, a direct MCP call or prompt injection through attacker-controlled Contentful content can redirect Contentful Management API requests and their Authorization header to an attacker-controlled host or proxy. The regular tools that use createToolClient are unaffected because those tools pin the host from server configuration. Exposure of the personal access token permits persistent out-of-band access to every Contentful space within the token's scope. This issue is fixed in @contentful/mcp-server 1.7.19 and @contentful/mcp-tools 0.4.5.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.7 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N | GitHub_M |
Weaknesses
- CWE-918 Server-Side Request Forgery (SSRF)
Affected Products
| Product | Versions |
|---|---|
contentful-mcp-servercontentful |
|
mcp-server@contentful |
|
mcp-tools@contentful |
|
References
- https://github.com/contentful/contentful-mcp-server/security/advisories/GHSA-2xhg-73j7-rrgx
- https://github.com/contentful/contentful-mcp-server/pull/376
- https://github.com/contentful/contentful-mcp-server/commit/fa7477ee48515f4248bc91a025eab0ca83423fe0
- https://github.com/contentful/contentful-mcp-server/releases/tag/mcp-server@1.7.19
- https://github.com/contentful/contentful-mcp-server/releases/tag/mcp-tools@0.4.5
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