CVE-2026-35568: Mcp core Java-SDK Has A DNS Rebinding Vulnerability
HIGHCVE-2026-35568 is a HIGH java-sdk has a dns rebinding vulnerability (CWE-346: Origin Validation Error) affecting Mcp core libraries in the Maven ecosystem. The issue involves java-sdk has a dns rebinding vulnerability. Remediation is available by upgrading affected packages to version 1.0.0.
CVE-2026-35568 at a Glance
How to Fix CVE-2026-35568
To remediate this vulnerability, upgrade all affected Mcp core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>io.modelcontextprotocol.sdk</groupId>
<artifactId>mcp-core</artifactId>
<version>1.0.0</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=io.modelcontextprotocol.sdkHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-35568, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=io.modelcontextprotocol.sdkAnalyze the terminal output to locate any version of Mcp core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.0), your application is affected.
Note: The mvn dependency:tree -Dincludes=io.modelcontextprotocol.sdk command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-346: Origin Validation Error, where the product does not properly verify that the source of data or communication is valid. In Mcp core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-35568 Affected Mcp core Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
io.modelcontextprotocol.sdk:mcp-core
|
Maven |
< 1.0.0
|
1.0.0
|
References
Frequently Asked Questions
What is CVE-2026-35568?
Which Mcp core versions are affected?
What version fixes CVE-2026-35568?
Is mcp-core affected?
What CWE is associated with CVE-2026-35568?
How can I check Maven dependencies for CVE-2026-35568?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-8jxr-pr72-r468",
"modified" : "2026-04-08T11:57:14Z",
"published" : "2026-04-07T20:13:32Z",
"aliases" : [ "CVE-2026-35568" ],
"summary" : "Java-SDK has a DNS Rebinding Vulnerability",
"details" : "### Summary\n\nThe java-sdk contains a DNS rebinding vulnerability. This vulnerability allows an attacker to access a locally or network-private java-sdk MCP server via a victims browser that is either local, or network adjacent.\n\nThis allows an attacker to make any tool call to the server as if they were a locally running MCP connected AI agent.\n\n### Details\n\nPrior to 1.0.0 no Origin header validation was occurring, in violation of the MCP specification. [Base Protocol > Transports: 2.0.1 Security Warning](https://modelcontextprotocol.io/specification/2025-06-18/basic/transports#security-warning):\n\n> 1: Servers MUST validate the Origin header on all incoming connections to prevent DNS rebinding attacks.\n\nWhen the web server serving HTTP traffic to the MCP server does not perform standard CORS checks, a DNS rebinding attack is possible.\n\nSome default server configurations and frameworks come with embedded `Origin` header validation. MCP servers built using those are not vulnerable to this issue. For example, the following are NOT vulnerable:\n- Spring AI\n\n### Impact\n\nAny developer connecting to a malicious website can inadvertently allow an attacker to make tool calls to local or private-network MCP servers.\n\n### Workarounds\n\nUsers can mitigate this risk by:\n1. Running the MCP server behind a reverse proxy (like Nginx or HAProxy) configured to strictly validate the `Host` and `Origin` headers.\n2. Using a framework that inherently enforces strict CORS and Origin validation (such as Spring AI).",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "io.modelcontextprotocol.sdk:mcp-core"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.0.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/modelcontextprotocol/java-sdk/security/advisories/GHSA-8jxr-pr72-r468"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35568"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/modelcontextprotocol/java-sdk"
}, {
"type" : "WEB",
"url" : "https://github.com/modelcontextprotocol/java-sdk/releases/tag/v1.0.0"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-346" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-04-07T20:13:32Z",
"nvd_published_at" : "2026-04-07T22:16:23Z"
}
}