CVE-2026-35577

Apollo MCP Server is a Model Context Protocol server that exposes GraphQL operations as MCP tools. Prior to version 1.7.0, the Apollo MCP Server did not validate the Host header on incoming HTTP requests when using StreamableHTTP transport. In configurations where an HTTP-based MCP server is run on localhost without additional authentication or network-level controls, this could potentially allow a malicious website—visited by a user running the server locally—to use DNS rebinding techniques to bypass same-origin policy restrictions and issue requests to the local MCP server. If successfully exploited, this could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the local user. This issue is limited to HTTP-based transport modes (StreamableHTTP). It does not affect servers using stdio transport. The practical risk is further reduced in deployments that use authentication, network-level access controls, or are not bound to localhost. This vulnerability is fixed in 1.7.0.

CVSS v3 6.8 MEDIUM

6.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/apollographql/apollo-mcp-server/pull/602
https://github.com/apollographql/apollo-mcp-server/pull/635
https://github.com/apollographql/apollo-mcp-server/security/advisories/GHSA-wqrj-vp8w-f8vh

Configurations

No configuration.

History

09 Apr 2026, 20:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-09 20:16

Updated : 2026-04-13 15:02

NVD link : CVE-2026-35577

Mitre link : CVE-2026-35577

CVE.ORG link : CVE-2026-35577

JSON object : View

Products Affected

No product.

CWE

CWE-346

Origin Validation Error

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