Is this vulnerability remotely exploitable?

Yes. If a repository accepts external contributions (for example, via pull requests) and runs them with `act`, an attacker can remotely influence workflow content or inputs so that untrusted data is echoed and interpreted as commands.

What level of access does an attacker need?

The attacker needs a way to control or significantly influence what a workflow step prints to stdout. This often means the ability to submit or modify workflow inputs, repository files, or scripts that are executed during the workflow.

What is the safest general fix pattern?

The safest pattern is to treat step output as data only: disable or remove support for deprecated text-based workflow commands and avoid interpreting stdout as control instructions. Where environment changes are necessary, make them explicit in workflow configuration rather than driven by step output.

Severity:

CRITICAL RISK

(9.8)

Environment Injection via Deprecated Workflow Commands (CWE-74) in act GitHub Actions Runner

CVE-2026-34041

Published:

Mar 30, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

Remote Code Execution on the Router

April 6, 2026

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Remote Code Execution on Router Firmware

April 6, 2026

Vulnerability Type

Category:

Environment Injection

CWE:

CWE-74

Impact:

Command and Environment Manipulation in CI Workflows

Severity:

CRITICAL RISK

(9.8)

CVSS Version:

3.1

Vulnerability Type

Category:

Environment Injection

CWE:

CWE-74

Impact:

Command and Environment Manipulation in CI Workflows

Severity:

CRITICAL RISK

(9.8)

CVSS Version:

3.1

Catch This CVE While Code Is Being Written

Detect vulnerable code directly in pull requests, so CVEs are fixed before merge.

Get Started

Ship clean & secure code faster

START 14 DAYS FREE TRIAL

BOOK A DEMO

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Made with Love in San Francisco

355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Environment Injection via Deprecated Workflow Commands (CWE-74) in act GitHub Actions Runner

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Product

Pricing

Company

Legal

Developers

Compare

Product

Pricing

Company

Legal

Developers

Compare

Product

Pricing

Company

Legal

Developers

Compare