CVE-2026-45609 mcp-security: Unvalidated URL Fetching (SSRF)
Attackers can exploit unvalidated URL fetching in mcp-security to access internal network resources when Dynamic Client Registration is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45609?
CVE-2026-45609 is a high-severity server-side request forgery vulnerability in spring-ai-community mcp-security, published on 29 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-918
Which versions are affected by CVE-2026-45609?
2 open source packages ship an affected version, including org.springaicommunity:mcp-client-security. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.springaicommunity:mcp-client-security Maven | All versions | 0.1.9 |
org.springaicommunity:mcp-client-security Maven | All versions | 0.1.9 |
Products include Springaicommunity Mcp Security.
How do I fix CVE-2026-45609?
Upgrade org.springaicommunity:mcp-client-security to 0.1.9 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-45609 being exploited?
There is no known exploitation of CVE-2026-45609 in the wild and no public exploit code.
Sources
Also known as GHSA-qjp4-4jvr-xqg3.