CVE-2026-45609: Spring AI MCP Security Unvalidated URL Fetching (SSRF) Vulnerability
HIGHCVE-2026-45609 is a HIGH (CVSS 7.2) unvalidated url fetching (ssrf) vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Spring AI MCP Security libraries in the Maven ecosystem. The issue involves unvalidated url fetching (ssrf). Remediation is available by upgrading affected packages to version 0.1.9.
CVE-2026-45609 at a Glance
Security Impact
CVSS: 7.2
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N).
How to Fix CVE-2026-45609
To remediate this vulnerability, upgrade all affected Spring AI MCP Security 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>org.springaicommunity</groupId>
<artifactId>mcp-client-security</artifactId>
<version>0.1.9</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.springaicommunityHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-45609, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.springaicommunityAnalyze the terminal output to locate any version of Spring AI MCP Security in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.1.9), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.springaicommunity 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-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. In Spring AI MCP Security, 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-2026-45609 Affected Spring AI MCP Security Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.springaicommunity:mcp-client-security
|
Maven |
< 0.1.9
|
0.1.9
|
References
Frequently Asked Questions
What is CVE-2026-45609?
Which Spring AI MCP Security versions are affected?
What version fixes CVE-2026-45609?
Is mcp-client-security affected?
What is the CVSS score of CVE-2026-45609?
What CWE is associated with CVE-2026-45609?
How can I check Maven dependencies for CVE-2026-45609?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-qjp4-4jvr-xqg3",
"modified" : "2026-06-09T10:29:26Z",
"published" : "2026-05-18T13:29:29Z",
"aliases" : [ "CVE-2026-45609" ],
"summary" : "Spring AI MCP Security: Unvalidated URL Fetching (SSRF)",
"details" : "### Summary\n\nThe mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) [security specifications](https://modelcontextprotocol.io/docs/tutorials/security/security_best_practices#mitigation-3). Specifically, it processes untrusted URLs for OAuth-related discovery and metadata without verifying if the targets are malicious or internal to the network.\n\nThis only affects installations with Dynamic Client Registration (DCR) enabled:\n\n```properties\nspring.ai.mcp.client.authorization.dynamic-client-registration.enabled=true\n```\n\nDCR does not validate URLs exposed by MCP Servers (protected resource metadata URL, authorization server URL) and Authorization Servers (all OAuth2 endpoints).\n\n### Workaround\n\nWhen users need to perform DCR, they may provide their own `McpOAuth2ClientManager`. Both `McpMetadataDiscoveryService` and `DynamicClientRegistrationService` are also affected, if used, users should provide their own subclasses.\n\nAlternatively, users can provide the default implementations of these classes with a `RestClient` that implements URL filtering through `ClientHttpRequestInterceptor`.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.springaicommunity:mcp-client-security"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.1.9"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/spring-ai-community/mcp-security/security/advisories/GHSA-qjp4-4jvr-xqg3"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45609"
}, {
"type" : "WEB",
"url" : "https://github.com/spring-ai-community/mcp-security/pull/68"
}, {
"type" : "WEB",
"url" : "https://github.com/spring-ai-community/mcp-security/commit/e6b67d8a67cd7acbee6e4c0741c385d62e3ed576"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/spring-ai-community/mcp-security"
}, {
"type" : "WEB",
"url" : "https://github.com/spring-ai-community/mcp-security/releases/tag/v0.1.9"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-918" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-05-18T13:29:29Z",
"nvd_published_at" : "2026-05-29T15:16:23Z"
}
}