CVE-2026-75060 in PyCharm
Summary
by MITRE • 08/17/2026
In JetBrains PyCharm before 2026.2.1 code execution was possible via unauthenticated Jupyter MCP tools
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Analysis
by VulDB Data Team • 08/17/2026
The vulnerability identified in versions of JetBrains PyCharm prior to version 2026.2.1 represents a critical security flaw within the integrated development environment's support for Jupyter Notebooks and Model Context Protocol (MCP) integrations. This issue stems from an insufficient authentication mechanism governing the interaction between the IDE client and external tools or services that adhere to the MCP specification. The Model Context Protocol is designed to facilitate communication between large language models and various data sources, but its implementation in PyCharm failed to enforce strict access controls on certain endpoints exposed through this interface. Consequently, any user with network-level access to a machine running an affected version of PyCharm could potentially interact with these unauthenticated Jupyter MCP tools without providing valid credentials or security tokens.
From a technical perspective, the core flaw lies in the handling of incoming requests directed at specific API endpoints associated with Jupyter kernel management and tool execution via MCP. The application did not adequately validate the source or authenticity of these requests before processing them for code execution. This lack of input validation and authentication checks allows an attacker to craft malicious payloads that are interpreted as legitimate commands by the IDE's backend processes. When such a payload is received, PyCharm proceeds to execute the contained instructions within the context of the user session running the application. Because development environments often possess elevated privileges relative to standard applications or have access to sensitive project files and system resources, this capability transforms a simple remote interaction into a severe code execution vector.
The operational impact of this vulnerability is significant for developers who utilize PyCharm with Jupyter notebooks and MCP-enabled extensions. An attacker exploiting this flaw could achieve arbitrary command execution on the host machine under the context of the user running PyCharm. This can lead to full system compromise, including the theft of sensitive source code, intellectual property, API keys stored in environment variables or configuration files, and credentials cached by other applications. Furthermore, because Jupyter kernels often run with the permissions of the invoking user, an attacker could pivot from this initial access to attack other systems on the local network if the compromised machine serves as a gateway or has trust relationships with internal assets. The unauthenticated nature of the exploit means that no prior compromise is necessary; mere connectivity to the target port where PyCharm listens for these MCP connections is sufficient to initiate an attack, broadening the potential attack surface significantly in shared development environments or public-facing setups.
This vulnerability aligns closely with CWE-287 Improper Authentication and CWE-94 Command Injection via Untrusted Control Sequences within the Common Weakness Enumeration framework. The failure to verify identity before allowing execution of commands constitutes a classic authentication bypass that leads directly to code injection risks. In terms of offensive security tactics, this scenario maps to MITRE ATT&CK techniques involving Remote Services such as SSH or custom protocols for initial access and Command Line Interface usage for lateral movement and data exfiltration. The exploitation path leverages the trusted relationship between the IDE and its plugins or external tools, abusing that trust to execute arbitrary code without detection by standard security controls that might not monitor intra-process communication within development tools.
Mitigation strategies must prioritize immediate software updates as the primary defense vector. JetBrains has addressed this issue in version 2026.2.1 and subsequent releases by implementing stricter authentication requirements for all Jupyter MCP tool interactions. Organizations should ensure that their development workstations are patched to at least this version immediately. In addition to updating, administrators should enforce network segmentation policies to restrict access to IDE ports from untrusted networks or external IP addresses. If PyCharm is configured to accept remote connections, it is advisable to disable unnecessary services and limit exposure only to trusted internal subnets where developers operate. Security teams should also monitor for unusual outbound traffic patterns originating from development machines that could indicate exploitation attempts or post-exploitation activities such as data staging or command-and-control communications associated with the MCP protocol abuse.