CVE-2026-45609
SSRF Vulnerability in mcp-security Framework
Publication date: 2026-05-29
Last updated on: 2026-05-29
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| spring-ai-community | mcp-security | to 0.1.9 (exc) |
| spring-ai-community | mcp-security | 0.1.9 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-918 | 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-45609 is a Server-Side Request Forgery (SSRF) vulnerability in the MCP Client component of the spring-ai-community/mcp-security framework. The issue arises because the framework processes untrusted URLs related to OAuth discovery and metadata without validating whether these URLs are malicious or internal to the network.
This vulnerability specifically affects installations with Dynamic Client Registration (DCR) enabled and occurs due to the failure to implement mandatory SSRF mitigations as outlined in the Model Context Protocol (MCP) security specifications.
The flaw allows attackers to potentially make unauthorized network requests by exploiting the unvalidated URL fetching mechanism.
How can this vulnerability impact me? :
This vulnerability can allow attackers to perform unauthorized network requests from the affected system, potentially accessing internal network resources or malicious external servers.
Because the vulnerability involves unvalidated URL fetching, it could be exploited to access sensitive internal services or data that are not normally exposed externally.
The CVSS score of 7.2 indicates a high severity impact, with potential confidentiality and integrity loss, but no impact on availability.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves unvalidated URL fetching (SSRF) in the MCP Client component when processing OAuth-related discovery and metadata URLs without proper validation. Detection involves identifying if your system is running a vulnerable version of the mcp-security framework (prior to 0.1.9) with Dynamic Client Registration (DCR) enabled.
To detect potential exploitation or attempts, you can monitor network traffic for unusual outbound requests to internal or unexpected URLs originating from the MCP Client component.
While no specific commands are provided in the resources, general detection steps include:
- Check the installed version of mcp-security to confirm if it is prior to 0.1.9.
- Use network monitoring tools (e.g., tcpdump, Wireshark) to capture outbound HTTP requests from the affected system and analyze for suspicious internal or external URL fetches.
- Review application logs for OAuth-related discovery or metadata fetch operations that involve untrusted URLs.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability immediately, upgrade the mcp-security framework to version 0.1.9 or later, where the SSRF issue is fixed.
If upgrading is not immediately possible, users can mitigate the risk by providing custom implementations of the affected services or configuring a RestClient with URL filtering to prevent untrusted or internal URLs from being fetched.
Additionally, ensure that Dynamic Client Registration (DCR) is disabled if it is not required, as the vulnerability only affects installations with DCR enabled.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify how the CVE-2026-45609 vulnerability impacts compliance with common standards and regulations such as GDPR or HIPAA.