CVE-2026-30643: DedeCMS 5.7.118 RCE Vulnerability

CVE-2026-30643 Overview

CVE-2026-30643 is a critical Code Injection vulnerability discovered in DedeCMS version 5.7.118. The vulnerability allows remote attackers to execute arbitrary code on affected systems by crafting malicious setup tag values within a module upload operation. This flaw stems from improper input validation during the module installation process, enabling unauthenticated attackers to achieve full system compromise.

Critical Impact

This vulnerability enables remote code execution without authentication, allowing attackers to gain complete control over affected DedeCMS installations and potentially pivot to other systems within the network.

Affected Products

• DedeCMS 5.7.118

Discovery Timeline

• 2026-04-01 - CVE-2026-30643 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2026-30643

Vulnerability Analysis

This vulnerability is classified under CWE-94 (Improper Control of Generation of Code - Code Injection). The flaw exists in how DedeCMS processes setup tag values during module upload operations. When a user uploads a module, the application fails to properly sanitize or validate the configuration parameters embedded within the module's setup tags.

The vulnerability allows attackers to inject malicious code through specially crafted module packages. When the module installation routine processes these tainted setup tag values, the injected code is executed within the context of the web application, typically with the same privileges as the web server process.

Due to the network-accessible nature of this vulnerability and the lack of authentication requirements, attackers can remotely exploit affected installations without any user interaction. Successful exploitation results in complete compromise of confidentiality, integrity, and availability of the target system.

Root Cause

The root cause of this vulnerability lies in the insufficient input validation and sanitization of setup tag values within DedeCMS's module upload functionality. The application directly processes user-controlled data from uploaded module configuration without properly escaping or filtering potentially dangerous constructs, allowing arbitrary code injection.

Attack Vector

The attack vector is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Crafting a malicious DedeCMS module package containing specially crafted setup tag values
2. Uploading the module through the module installation interface
3. The malicious code embedded in the setup tags executes during the module processing phase
4. The attacker gains code execution with the privileges of the web server

The vulnerability is accessible over the network, has low attack complexity, and requires no privileges or user interaction, making it highly exploitable.

Detection Methods for CVE-2026-30643

Indicators of Compromise

• Unexpected module installations or uploads in DedeCMS administration logs
• Suspicious PHP files or web shells appearing in the module directories
• Unusual outbound network connections from the web server process
• Modified or newly created files in DedeCMS installation directories

Detection Strategies

• Monitor web server logs for unusual module upload requests, particularly those with encoded or obfuscated parameters
• Implement file integrity monitoring on DedeCMS installation directories to detect unauthorized modifications
• Deploy web application firewalls (WAF) with rules to detect code injection patterns in upload requests
• Review PHP error logs for code execution anomalies or unexpected include/require operations

Monitoring Recommendations

• Enable verbose logging for the DedeCMS administration panel and module management functionality
• Configure alerts for any new file creation or modification within the DedeCMS module directories
• Implement network-level monitoring for suspicious outbound connections from the web server
• Regularly audit installed modules against a known-good baseline

How to Mitigate CVE-2026-30643

Immediate Actions Required

• Restrict access to the DedeCMS module upload functionality to trusted administrators only
• Implement network-level access controls to limit who can access the administration panel
• Review recently installed modules for any unauthorized or suspicious additions
• Consider temporarily disabling the module upload functionality until a patch is available

Patch Information

As of the last NVD update on 2026-04-01, consult the DedeCMS Official Site for the latest security updates and patching guidance. A proof-of-concept repository is available at the GitHub PoC Repository which provides additional technical details about the vulnerability.

Workarounds

• Restrict access to the DedeCMS administrative interface using IP-based allowlisting or VPN requirements
• Implement a Web Application Firewall (WAF) with rules to block requests containing code injection patterns
• Disable the module upload functionality entirely if not required for operations
• Place the DedeCMS installation behind an authenticated reverse proxy for additional access control

# Example: Apache configuration to restrict admin access by IP
<Directory "/var/www/html/dedecms/dede/">
    Require ip 192.168.1.0/24
    Require ip 10.0.0.0/8
</Directory>