CVE-2026-53957 PUBLISHED

Contentful MCP Server: export_space/import_space tools pass LLM-controlled `host`/`proxy` args to CMA client, redirecting server PAT to attacker-controlled endpoint

Assigner: GitHub_M
Reserved: 11.06.2026 Published: 15.09.2026 Updated: 15.09.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CVSS Score: 7.7

Product Status

Vendor contentful
Product contentful-mcp-server
Versions
  • Version < 1.7.19 is affected
Vendor @contentful
Product mcp-server
Versions
  • Version < 1.7.19 is affected
Vendor @contentful
Product mcp-tools
Versions
  • Version < 0.4.5 is affected

References

Problem Types

  • CWE-918: Server-Side Request Forgery (SSRF) CWE