CVE-2026-73895 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 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 3.2.18. This security flaw represents a significant risk to organizations relying on this framework for building reactive microservices and web applications in Java environments. The core issue stems from an improper access control mechanism that fails to adequately restrict data exposure based on user authentication status or role-based permissions. As a result, the server inadvertently exposes internal state information or sensitive configuration details through standard HTTP endpoints without requiring valid credentials. This misconfiguration allows any remote actor with network connectivity to interact with these exposed interfaces and retrieve data that should remain confidential within the application context.
From an operational perspective, this vulnerability enables unauthenticated attackers to perform unauthorized read access against a subset of Helidon accessible data. The impact is primarily confined to confidentiality, as indicated by the CVSS 3.1 base score of 5.3 with a vector of AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N. While there is no direct indication of integrity or availability impacts such as remote code execution or denial of service in this specific instance, the leakage of internal data can have severe downstream consequences. Exposed information may include session tokens, user identifiers, database connection strings, or other metadata that aids attackers in crafting more sophisticated follow-up attacks. This aligns with CWE-200, which classifies Information Exposure as a vulnerability where sensitive information is disclosed to unauthorized actors without explicit intent by the software developer.
The attack vector leverages standard HTTP protocols, meaning no special tools or complex exploitation techniques are required beyond basic network access and knowledge of the affected endpoint structure. The low complexity score reflects that an attacker does not need specific user interaction or high-level privileges to trigger this data leak. This characteristic places the vulnerability within the ATT&CK framework under tactics related to Collection and Discovery, specifically mapping to techniques where adversaries gather information about a target environment through passive observation or active probing of exposed services. The lack of authentication requirements makes it particularly dangerous in public-facing deployments where such endpoints might be inadvertently indexed by search engines or scanned by automated threat intelligence tools.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Oracle has likely released a patch for version 3.2.18, so the primary action is to upgrade to the latest supported release of Helidon where this access control logic has been corrected. In environments where upgrading is not immediately feasible, network-level controls such as Web Application Firewalls can be configured to block requests targeting specific sensitive endpoints or patterns associated with data leakage. Additionally, developers should audit their use of reactive web handlers to ensure that all public APIs enforce strict authentication and authorization checks before returning any response body. Implementing comprehensive logging and monitoring for anomalous access patterns from unauthenticated sources will also aid in early detection of exploitation attempts. Regular security assessments using static application security testing tools can help identify similar misconfigurations across the codebase, ensuring adherence to secure coding standards like OWASP API Security Top 10, particularly regarding broken object level authorization principles.