CVE-2025-69256: The Serverless Framework is a framework for using AWS Lambda and other managed cloud services to build applications. Starting in version 4.29.0 and pr...

Description

The Serverless Framework is a framework for using AWS Lambda and other managed cloud services to build applications. Starting in version 4.29.0 and prior to version 4.29.3, a command injection vulnerability exists in the Serverless Framework's built-in MCP server package (@serverless/mcp). This vulnerability only affects users of the experimental MCP server feature (serverless mcp), which represents less than 0.1% of Serverless Framework users. The core Serverless Framework CLI and deployment functionality are not affected. The vulnerability is caused by the unsanitized use of input parameters within a call to `child_process.exec`, enabling an attacker to inject arbitrary system commands. Successful exploitation can lead to remote code execution under the server process's privileges. The server constructs and executes shell commands using unvalidated user input directly within command-line strings. This introduces the possibility of shell metacharacter injection (`|`, `>`, `&&`, etc.). Version 4.29.3 fixes the issue.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.94%

77.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-77

Affected Software

Vendor	Product	Versions
Serverless	Serverless	>= 4.29.0, < 4.29.3

References

Timeline

Published: Dec 30, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-69256?

The Serverless Framework is a framework for using AWS Lambda and other managed cloud services to build applications. Starting in version 4.29.0 and prior to version 4.29.3, a command injection vulnerability exists in the Serverless Framework's built-in MCP server package (@serverless/mcp). This vulnerability only affects users of the experimental MCP server feature (serverless mcp), which represents less than 0.1% of Serverless Framework users. The core Serverless Framework CLI and deployment functionality are not affected. The vulnerability is caused by the unsanitized use of input parameters within a call to `child_process.exec`, enabling an attacker to inject arbitrary system commands. Successful exploitation can lead to remote code execution under the server process's privileges. The server constructs and executes shell commands using unvalidated user input directly within command-line strings. This introduces the possibility of shell metacharacter injection (`|`, `>`, `&&`, etc.). Version 4.29.3 fixes the issue.

How severe is CVE-2025-69256?

CVE-2025-69256 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.94% probability of exploitation in the next 30 days.

How do I fix CVE-2025-69256?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.