dbcve.org
Mcp Java SdkApplication · Lfprojects

CVE-2026-35568

MEDIUM · 5.7 CVSS v3.1 Published 2026-04-07
Fix available
A fix is available. Upgrade to 1.0.0 or later.
See remediation →
60/100
Remediation priority · Elevated
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The MCP Java SDK prior to version 1.0.0 contains a DNS rebinding vulnerability that allows attackers to bypass network isolation protections. By manipulating DNS resolution, an attacker can trick a victim's browser into making requests to locally or network-adjacent MCP servers, enabling unauthorized tool calls as if the attacker were a legitimate locally-connected AI agent.

MitigationUpgrade the MCP Java SDK to version 1.0.0 or later, which includes DNS rebinding protection fixes. Verify all MCP server endpoints implement proper hostname validation and consider adding explicit allowlists for trusted sources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mcp Java SdkApplication
Affected:< 1.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate the MCP Java SDK in your project
    Search your project dependencies for 'mcp' or 'modelcontextprotocol' in build files (pom.xml, build.gradle), lib directories, or JAR manifests
    Affected if The MCP Java SDK library is present in your project dependencies
  2. Identify the installed MCP Java SDK version
    Check your dependency management file (pom.xml, build.gradle, requirements.txt) for the exact version of the MCP Java SDK, or inspect the JAR file META-INF/MANIFEST.MF
    Affected if The version is anything less than 1.0.0 (e.g., 0.9.x, 0.8.x, etc.)
  3. Determine if your MCP server binds to network interfaces
    Review your MCP server configuration or startup scripts for the binding address. Look for configurations like '0.0.0.0', external IP addresses, or non-loopback interfaces. Check the --host or server bind parameter in your launch configuration
    Affected if The server is bound to 0.0.0.0, an external IP, or any address other than 127.0.0.1/localhost
  4. Verify DNS rebinding protections are not in place
    Check your server startup configuration or network layer for DNS rebinding defenses such as DNS pinning, host header validation, or an allowlist of permitted hostnames
    Affected if No DNS rebinding protections are configured and the server is network-accessible

Your environment is affected if you are running any version of the MCP Java SDK prior to 1.0.0 and your MCP server is accessible to browsers on network interfaces other than localhost without DNS rebinding defenses.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.0.0 or later
Fixed in 1.0.0
Interim mitigation

Upgrade the MCP Java SDK to version 1.0.0 or later, which includes DNS rebinding protection fixes. Verify all MCP server endpoints implement proper hostname validation and consider adding explicit allowlists for trusted sources.

Recommended fix High confidence

1.0.0

  1. Locate the Mcp Java SDK dependency in your project's dependency management file (e.g., pom.xml for Maven or build.gradle for Gradle)
  2. Update the dependency version to 1.0.0 or later
  3. Rebuild and test your application to ensure the MCP server/client functionality works correctly after the upgrade
Caveat Review the 1.0.0 release notes for any API or behavioral changes from earlier versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mcp Java Sdk Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-35568 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-35568 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data