Source URL: https://embracethered.com/blog/posts/2025/security-advisory-anthropic-slack-mcp-server-data-leakage/
Source: Embrace The Red
Title: Security Advisory: Anthropic’s Slack MCP Server Vulnerable to Data Exfiltration
Feedly Summary: This is a security advisory for a data leakage and exfiltration vulnerability in a popular, but now deprecated and unmaintained, Slack MCP Server from Anthropic.
If you are using this MCP server, or run an “MCP Store” that hosts it, it is advised that you analyze how this threat applies to your use case and apply a patch as needed.
Anthropic’s Slack MCP Server When Anthropic introduced MCP they published reference server implementations on Github.
AI Summary and Description: Yes
Summary: The text discusses a security advisory regarding a vulnerability in the deprecated Slack MCP Server from Anthropic, highlighting the risks of data leakage and exfiltration. It is essential for organizations still using this server to assess their vulnerability and apply necessary patches.
Detailed Description: The advisory addresses a critical security issue associated with the Slack MCP Server, emphasizing its potential for data leakage and exfiltration. Here are the significant points of the advisory:
– **Vulnerability Identification**: The notice details an identified vulnerability in a popular but deprecated server product without ongoing support or maintenance. This raises immediate concerns about the risks for current users.
– **Call to Action**: Users of the MCP server, especially those running an “MCP Store,” are urged to assess the applicability of the threat to their specific use case. This underscores the importance of proactive security management, particularly for outdated software.
– **Patch Implementation**: The text advises users to apply necessary patches to mitigate the impact of the identified vulnerability, indicating that while the software is no longer maintained, users still have some control to protect their environments.
– **Historical Context**: Mentioning the server’s introduction and reference implementations on Github provides context on the origins and status of the MCP Server. It underscores the importance of code review and security practices, even for deprecated projects.
**Practical Implications**:
– Organizations should conduct an immediate risk assessment regarding legacy systems, especially those that might handle sensitive data.
– Staying updated on security advisories for deprecated software is essential for preventing potential data breaches.
– It may be necessary to explore alternatives to deprecated systems to ensure long-term security and support.
This advisory serves as a reminder of the importance of maintaining security best practices in cloud environments and the need for compliance with evolving security standards.