Is there a public exploit for CVE-2026-111770?

Yes. Proof-of-concept code for CVE-2026-111770 has been published publicly.

Is there a proof of concept for CVE-2026-111770?

Yes — 1 proof-of-concept entry is linked on this page, from public repositories and community submissions. They are listed for authorised testing only.

How severe is CVE-2026-111770?

CVE-2026-111770 scores CVSS 7.7 (v3.1), rated high.

What does CVE-2026-111770 affect?

CVE-2026-111770 affects @modelcontextprotocol, modelcontextprotocol typescript-sdk, Server. It is part of the AI and agent stack (Model Context Protocol).

7.7 High

The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol.

CVE-2026-111770

The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. From 2.0.0 until 2.3.0 in @modelcontextprotocol/server, applications that shared one stateless HTTP transport or one McpServer or Server instance among multiple clients could deliver responses and notifications to the wrong client. The affected surface is an MCP server reached over HTTP by multiple clients. The trigger is reuse of one stateless transport or server instance. Messages were associated with a connection using only the JSON-RPC request identifier. SDK clients start request identifiers at zero, so collisions occur in normal operation. Cross-client delivery exposes one client's responses and notifications to another client. The issue requires an HTTP endpoint reachable by more than one client and an application that constructs the server or transport once at startup instead of once per request or session. stdio servers and factory-created per-call servers are not affected. Upgrading causes reused instances to fail and therefore requires an application code change. This issue is fixed in @modelcontextprotocol/server 2.3.0.

Proof-of-concept code is published

Public PoC

Public PoChahahahahahahahah6/mcp-idprobe

Signals come from Exploit-DB, Metasploit, Nuclei and published proof-of-concept repositories. Their absence means nothing was found, not that nothing exists.

Part of the AI stack

This affects Model Context Protocol, in MCP & tool servers.

Assessment

CVSS: 7.7 (v3.1)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Public PoC
Published: 5 November 2026
Last updated: 5 November 2026
Affected: @modelcontextprotocol · modelcontextprotocol · Server · typescript-sdk
Assigner: GitHub_M

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

At the source

EUVD (ENISA)

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

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Query this programmatically

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curl https://cve.zerocrew.in/api/cve/CVE-2026-111770