CVE-2026-71157 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 4.5.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized read access to a subset of Helidon accessible data. CVSS 3.1 Base Score 5.3 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 4.5.0. This security flaw represents a significant risk to organizations relying on this framework for building microservices and cloud-native applications in Java environments. The core issue stems from an improper access control mechanism that fails to adequately restrict unauthenticated requests targeting specific internal endpoints or data structures exposed by the web server implementation. Because the vulnerability is easily exploitable, it lowers the barrier for entry significantly, allowing adversaries with basic networking knowledge to leverage this weakness without requiring complex exploit development techniques or prior authentication credentials.
From a technical perspective, the flaw allows an attacker who has network access via HTTP to compromise the integrity of the Helidon application's data confidentiality. The attack vector is classified as Network-based with Low Attack Complexity and requires no User Interaction, indicating that automated scanning tools can readily detect and exploit this condition across vulnerable deployments. The primary operational impact is unauthorized read access to a subset of accessible data within the Helidon context. This means that sensitive information processed or stored by applications built on Helidon 4.5.0 could be exfiltrated by external actors, leading to potential data breaches without any alteration to system integrity or availability.
In terms of industry standard classifications, this vulnerability aligns with CWE-287, which describes Improper Authentication, as the server fails to verify the identity of the requester before granting access to protected resources. Furthermore, it maps to ATT&CK technique T1078, Valid Accounts, although in this specific case, the attacker exploits a lack of authentication requirement rather than stolen credentials, effectively bypassing security controls through misconfiguration or implementation errors in the web server's request handling logic. The CVSS 3.1 base score of 5.3 reflects a Medium severity level, driven primarily by Confidentiality impacts while Integrity and Availability remain unaffected according to the provided vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
To mitigate this risk, organizations running Helidon 4.5.0 should immediately apply the latest security patches or upgrade to a newer version of Oracle Fusion Middleware where this access control flaw has been resolved. It is critical to review application configurations to ensure that sensitive endpoints are not exposed unnecessarily and to implement additional network-level controls such as Web Application Firewalls (WAFs) that can filter out malicious requests targeting these vulnerable paths until the software update is applied. Regular security assessments and penetration testing should be conducted to identify similar misconfigurations in other components of the middleware stack, ensuring a defense-in-depth approach against unauthorized data access attempts.