# 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.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 May 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-qjp4-4jvr-xqg3

## 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 (Server-Side Request Forgery)

## 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 | Ecosystem | 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: Springaicommunity Mcp Security.

## How do I fix CVE-2026-45609?

Upgrade org.springaicommunity:mcp-client-security to 0.1.9 or later.

## Is CVE-2026-45609 being exploited?

There is no known exploitation of CVE-2026-45609 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45609 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-45609 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.springaicommunity:mcp-client-security (Maven): affected all versions; fixed in 0.1.9
- org.springaicommunity:mcp-client-security (Maven): affected all versions; fixed in 0.1.9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45609/ (Markdown: https://insights.sbomify.com/CVE-2026-45609/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45609
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45609
- OSV: https://osv.dev/vulnerability/CVE-2026-45609

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45609/
Summaries are generated and may contain mistakes; the official description above is the record.