# CVE-2026-35568: MCP Java-SDK has a DNS Rebinding Vulnerability

> An attacker can exploit DNS rebinding to access private MCP servers via a victim's browser, enabling unauthorized tool calls and potential code execution.

- **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 7 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-8jxr-pr72-r468, MINI-7462-v2ff-7m68, MINI-cfvw-qr57-hhj5

## What is CVE-2026-35568?

CVE-2026-35568 is a high-severity server-side request forgery vulnerability in modelcontextprotocol java-sdk, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to 1.0.0, the java-sdk contains a DNS rebinding vulnerability. This vulnerability allows an attacker to access a locally or network-private java-sdk MCP server via a victims browser that is either local, or network adjacent. This allows an attacker to make any tool call to the server as if they were a locally running MCP connected AI agent. This vulnerability is fixed in 1.0.0.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-35568?

2 open source packages ship an affected version, including io.modelcontextprotocol.sdk:mcp-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.modelcontextprotocol.sdk:mcp-core` | Maven | All versions | 1.0.0 |
| `io.modelcontextprotocol.sdk:mcp-core` | Maven | All versions | 1.0.0 |

Products: Lfprojects Mcp Java Sdk.

## How do I fix CVE-2026-35568?

Upgrade io.modelcontextprotocol.sdk:mcp-core to 1.0.0 or later.

## Is CVE-2026-35568 being exploited?

There is no known exploitation of CVE-2026-35568 in the wild and no public exploit code.

## Other vulnerabilities in modelcontextprotocol java-sdk

- [CVE-2026-34237](https://insights.sbomify.com/CVE-2026-34237/): MCP Java SDK has a Hardcoded Wildcard CORS (Access-Control-Allow-Origin: *) (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35568 and fix it if it is affected.

What it is: CVE-2026-35568 is a high-severity server-side request forgery vulnerability in modelcontextprotocol java-sdk, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-35568 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.modelcontextprotocol.sdk:mcp-core (Maven): affected all versions; fixed in 1.0.0
- io.modelcontextprotocol.sdk:mcp-core (Maven): affected all versions; fixed in 1.0.0

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-2026-35568/ (Markdown: https://insights.sbomify.com/CVE-2026-35568/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35568
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35568
- OSV: https://osv.dev/vulnerability/CVE-2026-35568

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-35568/
Summaries are generated and may contain mistakes; the official description above is the record.