High severity · published Sep 15, 2026
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
7.7
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
contentful-mcp-server · contentful
< 1.7.19 · source: vendor
MC
mcp-server · @contentful
< 1.7.19 · source: vendor
MC
mcp-tools · @contentful
< 0.4.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53957
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53957
github.com
https://github.com/contentful/contentful-mcp-server/commit/fa7477ee48515f4248bc91a025eab0ca83423fe0
github.com
https://github.com/contentful/contentful-mcp-server/pull/376
github.com
https://github.com/contentful/contentful-mcp-server/releases/tag/mcp-server@1.7.19
github.com
https://github.com/contentful/contentful-mcp-server/releases/tag/mcp-tools@0.4.5
github.com
https://github.com/contentful/contentful-mcp-server/security/advisories/GHSA-2xhg-73j7-rrgx
