CVE-2026-27674 Overview
A Code Injection vulnerability exists in SAP NetWeaver Application Server Java (Web Dynpro Java) that allows an unauthenticated attacker to supply crafted input that is interpreted by the application and causes it to reference attacker-controlled content. If a victim accesses the affected functionality, that attacker-controlled content could be executed in the victim's browser, potentially resulting in session compromise. This vulnerability enables the attacker to execute arbitrary client-side code, impacting the confidentiality and integrity of the application.
Critical Impact
Unauthenticated attackers can inject malicious code that executes in victim browsers, enabling session hijacking and arbitrary client-side code execution affecting data confidentiality and integrity.
Affected Products
- SAP NetWeaver Application Server Java (Web Dynpro Java)
Discovery Timeline
- April 14, 2026 - CVE-2026-27674 published to NVD
- April 14, 2026 - Last updated in NVD database
Technical Details for CVE-2026-27674
Vulnerability Analysis
This vulnerability is classified as CWE-94 (Improper Control of Generation of Code / Code Injection). The Web Dynpro Java component within SAP NetWeaver Application Server Java fails to properly validate and sanitize user-supplied input before processing it. This allows attackers to inject malicious content that the application subsequently references and serves to other users.
The vulnerability requires user interaction to exploit successfully. An attacker must craft malicious input and then entice a victim to access the affected functionality. When the victim interacts with the compromised component, the attacker-controlled content executes within the victim's browser context.
While the vulnerability does not impact system availability, it poses significant risks to confidentiality and integrity through potential session compromise and unauthorized data access.
Root Cause
The root cause lies in insufficient input validation and sanitization within the Web Dynpro Java component. The application accepts user-controlled input and incorporates it into content that is later served to other users without properly neutralizing potentially malicious code or references. This allows attackers to inject references to attacker-controlled content that the application subsequently loads and executes in victim browsers.
Attack Vector
The attack is network-based and can be initiated by unauthenticated attackers. The exploitation path involves:
- The attacker identifies the vulnerable Web Dynpro Java component in the target SAP NetWeaver Application Server
- Crafted malicious input is submitted to the vulnerable functionality, containing references to attacker-controlled content
- The application stores or processes this input without proper sanitization
- When a legitimate user accesses the affected functionality, the malicious content is referenced and executed in their browser
- The attacker-controlled code runs in the victim's browser context, potentially capturing session tokens, credentials, or other sensitive data
The attack requires user interaction as the victim must access the compromised functionality for the injected content to execute.
Detection Methods for CVE-2026-27674
Indicators of Compromise
- Unusual HTTP requests to SAP NetWeaver Web Dynpro Java endpoints containing encoded or obfuscated JavaScript
- Browser-initiated connections to unexpected external domains from users accessing SAP applications
- Session tokens appearing in HTTP requests to external servers
- Unexpected modifications to Web Dynpro Java component configurations or content
Detection Strategies
- Implement Web Application Firewall (WAF) rules to detect code injection patterns in requests to Web Dynpro Java components
- Monitor HTTP traffic for suspicious payloads containing script tags, event handlers, or encoded JavaScript
- Review SAP NetWeaver application logs for anomalous input patterns or error messages indicating injection attempts
- Deploy endpoint detection solutions to identify browser-based attacks originating from SAP application interactions
Monitoring Recommendations
- Enable detailed logging for SAP NetWeaver Application Server Java, particularly for Web Dynpro components
- Configure SIEM alerting for unusual authentication events or session activities following access to Web Dynpro functionality
- Monitor Content Security Policy (CSP) violation reports if implemented on SAP applications
- Track network connections from client browsers to identify potential data exfiltration to attacker-controlled servers
How to Mitigate CVE-2026-27674
Immediate Actions Required
- Review SAP Note #3719397 for vendor-specific guidance and apply recommended patches
- Restrict access to affected Web Dynpro Java components to authorized users only until patching is complete
- Implement additional input validation at the network perimeter using WAF rules
- Educate users about the risks of accessing untrusted links to SAP applications
Patch Information
SAP has released security updates addressing this vulnerability. Organizations should consult SAP Note #3719397 for detailed patch information and apply the appropriate updates for their SAP NetWeaver Application Server Java environment. Additional information about security updates is available through the SAP Security Patch Day portal.
Workarounds
- Implement strict Content Security Policy (CSP) headers to prevent execution of unauthorized scripts
- Deploy web application firewall rules to filter malicious input patterns targeting code injection vulnerabilities
- Limit network access to the SAP NetWeaver Application Server Java to trusted networks and users
- Enable additional authentication requirements for access to sensitive Web Dynpro Java components
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
