CVE-2026-73939 in Helidon
Summary
by MITRE • 08/19/2026
Vulnerability in the Helidon product of Oracle Fusion Middleware (component: Imperative Web Server). The supported version that is affected is 3.2.20. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. While the vulnerability is in Helidon, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized creation, deletion or modification access to critical data or all Helidon accessible data. CVSS 3.1 Base Score 8.6 (Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N).
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Analysis
by VulDB Data Team • 08/19/2026
The identified vulnerability resides within the Imperative Web Server component of Oracle Fusion Middleware Helidon, specifically affecting version 3.2.20. This security flaw represents a critical weakness in how the web server processes incoming HTTP requests from unauthenticated actors. The core technical issue stems from insufficient input validation or access control mechanisms inherent to the imperative programming model used by this specific module of the framework. Because the vulnerability allows for exploitation via standard network protocols without requiring any form of authentication, it presents a severe risk profile where remote attackers can interact directly with the server's internal logic through HTTP traffic. The ease of exploitation is heightened by the low complexity required to trigger the flaw, meaning that automated scanning tools or basic script-based attacks could successfully leverage this weakness against vulnerable instances exposed on public networks.
The operational impact of this vulnerability extends beyond the immediate Helidon application due to a scope change characteristic in CVSS scoring. While the technical root cause is located within Helidon, the successful exploitation can lead to unauthorized creation, deletion, or modification of critical data and all other data accessible by the Helidon process. This implies that if Helidon shares resources with other enterprise applications or databases through shared credentials, file system permissions, or network connectivity, those adjacent systems are also compromised. The integrity impact is rated as high, indicating that an attacker can alter application state, corrupt database records, or modify configuration files in a way that undermines the trustworthiness of the entire information system. This aligns with CWE-94, which describes improper control of generation of code (Code Injection), or potentially CWE-20 if it involves insufficient input validation leading to command injection or data manipulation.
From an offensive security perspective, this vulnerability maps directly to ATT&CK technique T1190, Exploit Public-Facing Application, as well as T1564, Hide Artifacts, depending on the specific method used to modify data without detection. The lack of authentication requirements places it firmly in the category of attacks that do not require user interaction or prior footholds, making them highly attractive for automated campaigns targeting internet-facing infrastructure. The high base score of 8.6 reflects the combination of network accessibility, low attack complexity, and significant integrity consequences. Attackers could potentially use this vector to inject malicious payloads into stored data, alter application logic by modifying configuration files, or delete critical records to cause denial of service through data loss rather than system crash.
Mitigation strategies must prioritize immediate patching if an updated version of Oracle Fusion Middleware Helidon is available that addresses the specific flaw in the Imperative Web Server component. In cases where patching is not immediately feasible, network-level controls should be implemented to restrict access to the affected service ports from untrusted networks. Implementing a Web Application Firewall with rulesets designed to detect and block anomalous HTTP request patterns associated with this vulnerability can provide an additional layer of defense. Furthermore, strict input validation and sanitization practices must be enforced at the application level for any custom code interacting with the Helidon server components. Regular security audits and penetration testing focused on authentication bypasses and data integrity violations are recommended to ensure that similar weaknesses do not persist in other parts of the middleware stack. Monitoring logs for unusual patterns of data modification or unauthorized access attempts can also aid in early detection of exploitation activities targeting this specific vulnerability.