CVE-2026-53710

What it is

MCP Context Forge is an AI gateway, registry, and proxy for MCP, A2A, REST, and gRPC APIs. Prior to 1.0.2, the python_sandbox_server in mcp-servers/python/python_sandbox_server/src/python_sandbox_server/server_fastmcp.py exposes raw getattr through safe_builtins, omits a required _getattr_ guard, and relies on validate_code checks for literal dangerous dunder strings. An attacker can construct dunder names at runtime, traverse the Python class hierarchy, reach subprocess.Popen, and execute OS commands with the server process privileges through the execute_code MCP tool. The HTTP/SSE transport can expose this tool without authentication, while stdio-only deployments have reduced network reachability. The issue affects the python_sandbox_server subproject and does not directly affect the core Context Forge gateway or proxy components. This issue is fixed in version 1.0.2.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

1.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-10 16:43 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-09-15 17:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-09-30 17:51 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.1% in the next 30 days (EPSS).
• Severity: 10.0 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-15 17:17 UTC

Last modified

2026-09-30 17:51 UTC

Exploit probability

1.1% · EPSS, next 30 days

Weakness

CWE-94 · Code injection

Record status

Deferred

Attack profile CVSS 3.1 · 10.0

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-53710.md and follow it. Check whether this project is affected by CVE-2026-53710. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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