CVE-2026-45609: Spring AI MCP Security: Unvalidated URL Fetching (SSRF)

Summary The 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/securit…

7.2CVSS Score

HIGHSeverity

NOCISA KEV

VulnerabilityImpact Type

📋 Vulnerability Details

CVE ID	CVE-2026-45609
Vendor	maven
Affected Product	org.springaicommunity:mcp-client-security
Vulnerability Type	Vulnerability
CVSS Score	7.2 (HIGH)
Actively Exploited	❌ No known exploitation
Patch Status	See Vendor Advisory →
Reported By	CYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

Summary The 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. This only affects installations with Dynamic Client Registration (DCR) enabled: ```properties`

spring.ai.mcp.client.authorization.dynamic-client-registration.enabled=true `` DCR does not validate URLs exposed by MCP Servers (protected resource metadata URL, authorization server URL) and Authorization Servers (all OAuth2 endpoints).

Workaround When users need to perform DCR, they m

🎯 Known Indicators of Compromise

{"type":"url","value":"https://modelcontextprotocol.io/docs/tutorials/security/security_best_practices#mitigation-3).","confidence_score":0.82,"first_seen":"2026-05-18","source_count":1} {"type":"domain","value":"modelcontextprotocol.io","confidence_score":0.75,"first_seen":"2026-05-18","source_count":1}

📚 Advisory References

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