{"id":"CVE-2026-45609","aliases":["EUVD-2026-33323","GHSA-qjp4-4jvr-xqg3"],"status":"published","title":"mcp-security: Unvalidated URL Fetching (SSRF)","description":"mcp-security provides Security and Authorization support for Model Context Protocol in Spring AI. Prior to 0.1.9, the mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) security specifications. 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 This vulnerability is fixed in 0.1.9.","severity":{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00207,"percentile":0.10934,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-918"],"published":"2026-05-18T13:29:29Z","modified":"2026-10-28T02:30:54Z","fixes":[{"ecosystem":"Maven","package":"org.springaicommunity:mcp-client-security","fixed_in":["0.1.9"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Maven","package":"org.springaicommunity:mcp-client-security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.9"}]}]},{"source":"osv","ecosystem":"Maven","package":"org.springaicommunity:mcp-client-security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.1.9"}]}],"versions":["0.0.1","0.0.2","0.0.3","0.0.4","0.0.5","0.0.6","0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8"]}],"products":[{"vendor":"spring-ai-community","product":"mcp-security"},{"vendor":"springaicommunity","product":"mcp_security"}],"references":[{"url":"https://github.com/spring-ai-community/mcp-security/security/advisories/GHSA-qjp4-4jvr-xqg3","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/spring-ai-community/mcp-security/pull/68","tags":["web"]},{"url":"https://github.com/spring-ai-community/mcp-security/commit/e6b67d8a67cd7acbee6e4c0741c385d62e3ed576","tags":["web"]},{"url":"https://github.com/spring-ai-community/mcp-security/releases/tag/v0.1.9","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45609","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-qjp4-4jvr-xqg3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45609.json","tags":["advisory"]},{"url":"https://github.com/spring-ai-community/mcp-security","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-45609","title":"mcp-security: Unvalidated URL Fetching (SSRF)","description":"mcp-security provides Security and Authorization support for Model Context Protocol in Spring AI. Prior to 0.1.9, the mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) security specifications. 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 This vulnerability is fixed in 0.1.9.","status":"published","published":"2026-05-29T13:48:06.703Z","modified":"2026-06-02T01:21:35.943Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T13:46:32.755125Z"}],"euvd":[{"id":"EUVD-2026-33323","description":"mcp-security provides Security and Authorization support for Model Context Protocol in Spring AI. Prior to 0.1.9, the mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) security specifications. 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 This vulnerability is fixed in 0.1.9.","status":"published","published":"2026-05-29T13:48:06Z","modified":"2026-06-02T01:21:35Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high"}],"updated_at":"2026-11-02T18:20:57.453624Z"}],"ghsa":[{"id":"GHSA-qjp4-4jvr-xqg3","title":"Spring AI MCP Security: Unvalidated URL Fetching (SSRF)","description":"### 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`.","status":"published","published":"2026-05-18T13:29:29Z","modified":"2026-06-09T10:29:29Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:40:22.540562Z"}],"nvd":[{"id":"CVE-2026-45609","description":"mcp-security provides Security and Authorization support for Model Context Protocol in Spring AI. Prior to 0.1.9, the mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) security specifications. 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 This vulnerability is fixed in 0.1.9.","status":"published","published":"2026-05-29T15:16:23.463Z","modified":"2026-07-21T12:10:00.09Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:12:21.244426Z"}],"osv":[{"id":"CVE-2026-45609","title":"mcp-security: Unvalidated URL Fetching (SSRF)","description":"mcp-security provides Security and Authorization support for Model Context Protocol in Spring AI. Prior to 0.1.9, the mcp-security framework fails to implement the mandatory SSRF mitigations outlined in the Model Context Protocol (MCP) security specifications. 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 This vulnerability is fixed in 0.1.9.","status":"published","published":"2026-05-29T13:48:06.703Z","modified":"2026-10-28T02:30:54.900570602Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:45:05.525666Z"},{"id":"GHSA-qjp4-4jvr-xqg3","title":"Spring AI MCP Security: Unvalidated URL Fetching (SSRF)","description":"### 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`.","status":"published","published":"2026-05-18T13:29:29Z","modified":"2026-06-09T10:45:18.369462455Z","cvss":[{"version":"3.1","score":7.2,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:46:54.760124Z"}]}}