CVE-2026-71166 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 3.2.18. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized creation, deletion or modification access to critical data or all Helidon accessible data as well as unauthorized access to critical data or complete access to all Helidon accessible data and unauthorized ability to cause a partial denial of service (partial DOS) of Helidon. CVSS 3.1 Base Score 9.4 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L).
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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 3.2.18. This security flaw represents a critical failure in input validation and access control mechanisms inherent to how the web server processes incoming HTTP requests. The nature of this defect allows an unauthenticated attacker who possesses network connectivity via standard HTTP protocols to exploit the weakness without requiring any prior authentication credentials or user interaction. Such conditions classify the vulnerability as highly accessible, enabling remote code execution scenarios where the attacker can manipulate the underlying application logic directly through crafted network packets.
From a technical perspective, the flaw likely stems from improper sanitization of input data passed to critical system functions within the Helidon framework. When an unauthenticated entity sends specifically constructed HTTP requests, the server fails to adequately validate or escape these inputs before processing them against database queries, file systems, or internal application states. This lack of rigorous boundary checking permits injection attacks that bypass intended security restrictions. The vulnerability aligns with Common Weakness Enumeration categories such as CWE-94 Improper Control of Generation of Code (Code Injection) and CWE-20 Improper Input Validation. These weaknesses allow the attacker to inject malicious commands or data structures that are interpreted by the server, leading to unauthorized operations on the host system.
The operational impact of this vulnerability is severe due to its high CVSS 3.1 Base Score of 9.4, which indicates a critical level of risk based on impacts to confidentiality, integrity, and availability. Successful exploitation grants an attacker comprehensive control over Helidon accessible data. This includes the ability to create new records, delete existing ones, or modify sensitive information without authorization. Furthermore, it allows for complete unauthorized access to all data that the Helidon application can reach, effectively compromising the entire data store associated with the middleware instance. Beyond data manipulation and exfiltration, the vulnerability also facilitates a partial denial of service condition. By consuming excessive server resources through malicious requests or causing internal errors, an attacker can degrade system performance or render specific services unavailable to legitimate users, thereby impacting business continuity.
In terms of threat modeling, this attack vector corresponds to MITRE ATT&CK techniques involving Initial Access via Network Service Exploitation and subsequent actions such as Data Manipulation and Impact through Denial of Service. The lack of authentication requirements places it firmly within the context of unauthenticated remote exploitation, which is among the most dangerous categories in cybersecurity due to its low barrier to entry for malicious actors. Attackers can automate the discovery and exploitation process using standard network scanning tools, making widespread compromise a significant risk if left unpatched.
Mitigation strategies must prioritize immediate remediation through vendor-provided updates. Organizations running Helidon version 3.2.18 should upgrade to the latest patched release where Oracle has addressed the input validation flaws within the Imperative Web Server component. In scenarios where patching is not immediately feasible, network-level controls such as Web Application Firewalls can be configured to inspect and block suspicious HTTP patterns indicative of injection attempts or resource exhaustion attacks. Additionally, implementing strict rate limiting on incoming connections can help mitigate the partial denial of service aspect by preventing a single source from overwhelming server resources. Regular security audits and penetration testing focused on input validation weaknesses are also recommended to ensure that similar vulnerabilities do not exist in other parts of the application stack.