External risk intelligence

Serverless-Devs 's init Command OS Command Injection

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-51190

This vulnerability affects a command-line interface tool used by developers for local project initialization. It requires a user to manually execute a specific command with malicious input on their local machine, making public internet exposure in common real-world deployments highly unlikely.

OS Command Injection

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability has been identified in a developer tool that could allow for the execution of unauthorized commands on a user's system if specific, user-initiated actions are taken. This issue relates to how the tool processes certain input formats, potentially enabling malicious commands to be run when the tool is used to initialize new projects. The primary concern is confirming if this tool and specific command usage are present within your development environments.

Malicious commands can run if a developer is tricked.
Confirms developer tool exposure and usage.
Assess if this tool is used in your environment.

Attack Path

How an attacker could exploit the issue

An attacker could trick a user into running a specific command, the "s init" command, with a specially crafted argument. This argument, when it ends with ".git", bypasses a security check and allows the attacker's input to be executed as an operating system command. This could lead to full system compromise.

Requires user to run a command.
Malicious input exploits command execution.
Risk of full system compromise.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, the "s init" command in Serverless-Devs could allow an attacker to execute arbitrary operating system commands. This could occur when a user runs the "s init" command with an argument controlled by an attacker, provided the argument ends in ".git" to bypass an input check. The impact is contingent on the user executing the vulnerable command with malicious input on their local machine.

OS commands on the user's machine.
Running "s init" with attacker-controlled input.
Arbitrary code execution may occur.

Operational Fix

Recommended remediation, mitigation, and detection steps

The `s init` command in Serverless-Devs is susceptible to OS command injection due to unsanitized user input. Teams responsible for development tooling and the application lifecycle should prioritize identifying instances of this tool within their environments. The immediate first step is to confirm its presence, assess its reachability and criticality, and then determine the accountable owner for remediation planning.

Development and Platform Teams
Verify tool usage and accessibility.
Plan and coordinate remediation efforts.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Serverless-Devs?

Serverless-Devs is a command-line interface tool that developers use to streamline the initialization and management of serverless projects. It helps automate the setup of cloud-native applications directly from a local development machine.

What does CWE-78 mean for CVE-2026-51190?

CWE-78, or OS Command Injection, means the software takes user-provided data and uses it to run system commands without properly cleaning it first. In this CVE, the tool fails to filter malicious input, allowing an attacker to execute unauthorized commands on the host system.

How is this vulnerability triggered?

The flaw is triggered when a user executes the 's init' command with an attacker-provided argument that ends in '.git'. This specific suffix bypasses the software's input filter, allowing the tool to pass the attacker's hidden code into the system's command processor. Simply running the tool without this specific, malicious input does not trigger the bug.

Is my environment at risk from this CVE?

Risk is low because the tool is typically used locally by developers. According to Halo Surface Signal, this requires manual execution of the 's init' command with malicious input, making it highly unlikely that an attacker could remotely exploit this over the internet in standard deployments.

Do I need to take action if I use Serverless-Devs?

Yes, you should first identify where this tool is installed within your development environment. Once located, confirm if your version is 3.1.11 or older. You should then coordinate with your development team to plan for updates and restrict the use of untrusted project sources.

References

gist.github.com/j311yl0v3u/5600afea3bea1337805c2e335bd4ae8e

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.