CVE-2026-26093: Owl OPDS Command Injection Vulnerability

CVE-2026-26093 Overview

CVE-2026-26093 is a command injection vulnerability affecting Owl OPDS version 2.2.0.4. The vulnerability stems from improper neutralization of special elements used in commands (CWE-77), allowing attackers to inject and execute arbitrary system commands through crafted network requests. This flaw enables authenticated attackers with network access to achieve remote code execution on vulnerable systems.

Critical Impact

Command injection vulnerabilities in Owl OPDS can allow attackers to execute arbitrary commands on the underlying system, potentially leading to complete system compromise, data exfiltration, or lateral movement within the network.

Affected Products

• Owl OPDS version 2.2.0.4

Discovery Timeline

• February 20, 2026 - CVE-2026-26093 published to NVD
• February 20, 2026 - Last updated in NVD database

Technical Details for CVE-2026-26093

Vulnerability Analysis

This command injection vulnerability in Owl OPDS arises from insufficient input validation when processing network requests. The application fails to properly sanitize user-supplied input before incorporating it into system commands, allowing attackers to inject malicious command sequences. When exploited, the injected commands execute with the privileges of the Owl OPDS application process, potentially providing attackers with substantial access to the underlying system.

The vulnerability requires network access and low-privilege authentication to exploit. Once successful, an attacker can achieve high impacts on confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of this vulnerability is the improper neutralization of special elements used in command construction (CWE-77). The Owl OPDS application does not adequately sanitize or escape user-controlled input before passing it to system shell commands. Characters such as semicolons (;), pipes (|), backticks (`), and other shell metacharacters can be leveraged to break out of the intended command context and inject additional malicious commands.

Attack Vector

The attack is conducted remotely over the network. An attacker with low-level privileges can craft a malicious network request containing command injection payloads. When the Owl OPDS application processes this request, the embedded commands are executed on the server.

The vulnerability allows command injection through specially crafted network requests to the Owl OPDS application. Attackers can embed shell metacharacters and arbitrary commands within request parameters, which are then executed by the underlying operating system. For detailed technical information, refer to the Nozomi Networks Vulnerability Advisory.

Detection Methods for CVE-2026-26093

Indicators of Compromise

• Unusual process spawning from the Owl OPDS application process, particularly shell processes (sh, bash, cmd.exe)
• Network requests containing shell metacharacters such as ;, |, &, $(), or backticks in request parameters
• Unexpected outbound network connections originating from the Owl OPDS server
• Anomalous system commands in application or web server logs

Detection Strategies

• Implement web application firewalls (WAF) with rules to detect command injection patterns in HTTP requests
• Deploy endpoint detection and response (EDR) solutions to monitor for suspicious process creation chains
• Configure intrusion detection systems (IDS) to alert on network traffic containing common command injection payloads
• Review application logs for requests containing shell metacharacters or unusual encoding patterns

Monitoring Recommendations

• Enable detailed logging for all network requests to the Owl OPDS application
• Monitor process creation events on systems running Owl OPDS for unexpected child processes
• Implement file integrity monitoring on critical system directories
• Set up alerts for any unusual network activity originating from the Owl OPDS server

How to Mitigate CVE-2026-26093

Immediate Actions Required

• Restrict network access to the Owl OPDS application to trusted IP addresses only
• Implement network segmentation to isolate Owl OPDS servers from critical infrastructure
• Deploy a web application firewall (WAF) with command injection detection rules
• Review and audit all network requests to identify potential exploitation attempts

Patch Information

Consult the Nozomi Networks Vulnerability Advisory for the latest patch information and vendor guidance. Organizations should monitor the Owl OPDS project for security updates addressing version 2.2.0.4.

Workarounds

• Implement strict input validation at the network perimeter using a reverse proxy or WAF
• Disable or restrict access to the affected functionality until a patch is available
• Run the Owl OPDS application with minimal privileges to limit the impact of successful exploitation
• Consider deploying the application in a sandboxed or containerized environment to contain potential breaches

# Example WAF rule to block common command injection patterns
# Add to your web application firewall configuration
# Block requests containing shell metacharacters
SecRule ARGS "@rx [;|`$()&]" "id:1001,phase:2,deny,status:403,msg:'Potential command injection attempt'"