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
export_space and import_space tools in @contentful/mcp-tools accept LLM-controlled host and proxy parameters that are spread directly into the options object passed to contentful-export / contentful-import. These libraries pass the merged options — including the attacker-controlled host — to the Contentful Management API (CMA) SDK, which builds baseURL from host and attaches the server’s CMA Personal Access Token as Authorization: Bearer <PAT> on every outgoing request. An attacker who can invoke MCP tools, or inject instructions into Contentful content the LLM reads, can redirect all CMA requests — and the PAT — to an attacker-controlled endpoint.
References
- github.com/advisories/GHSA-2xhg-73j7-rrgx
- github.com/contentful/contentful-mcp-server/commit/fa7477ee48515f4248bc91a025eab0ca83423fe0
- github.com/contentful/contentful-mcp-server/pull/376
- github.com/contentful/contentful-mcp-server/releases/tag/mcp-server%401.7.19
- github.com/contentful/contentful-mcp-server/releases/tag/mcp-tools%400.4.5
- github.com/contentful/contentful-mcp-server/security/advisories/GHSA-2xhg-73j7-rrgx
- nvd.nist.gov/vuln/detail/CVE-2026-53957
Code Behaviors & Features
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