Description

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 takeover of Helidon. CVSS 3.1 Base Score 9.8 (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:H).

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-18T21:18:24.027Z",
  "pubdate": "2026-08-18T21:18:24.027Z",
  "executiveSummary": "An easily exploitable vulnerability exists within the Oracle Fusion Middleware Helidon product, specifically affecting the Imperative Web Server component in version 4.5.0. This critical flaw allows an unauthenticated remote attacker with network access via the HTTP protocol to achieve a complete compromise and takeover of the affected Helidon instance. The vulnerability carries a maximum CVSS 3.1 Base Score of 9.8, indicating severe impacts across confidentiality, integrity, and availability. The attack vector is strictly network-based with low attack complexity, requiring no privileges or user interaction, which significantly elevates the overall risk profile. Successful exploitation grants the adversary full control over the application runtime, enabling them to read sensitive data, manipulate internal state, or disrupt service availability. Organizations utilizing the impacted version face immediate risks to their application infrastructure and must prioritize remediation efforts to prevent unauthorized remote exploitation.",
  "technicalDetails": "The vulnerability resides in the Imperative Web Server component of Oracle Helidon version 4.5.0. As an architectural component responsible for handling incoming HTTP request lifecycles, the Imperative Web Server processes network traffic directly from external clients. The root cause enables an unauthenticated remote attacker to interact with vulnerable parsing or handling routines exposed via the HTTP protocol without requiring any prior authentication credentials or interactive user session.\nExploitation occurs over the network via standard HTTP requests crafted to leverage flaws in the request processing logic of the vulnerable component. Because the attack complexity is low and the interface requires no privileges (PR:N, UI:N, S:U), an adversary can directly target the exposed HTTP listener endpoints of the Helidon instance. The attacker transmits a malicious payload encapsulated within HTTP traffic, which the Imperative Web Server improperly validates or handles.\nThe step-by-step attack flow begins with the attacker establishing a network connection to the HTTP port hosting the Helidon Imperative Web Server. The attacker then sends the specially crafted HTTP request designed to exploit the underlying vulnerability in the component logic. Due to insufficient input validation, memory safety issues, or flawed state handling within the server implementation, the payload executes within the context of the running application process. This breakdown in isolation and security controls permits unauthorized code execution or administrative function abuse.\nThe post-exploitation impact is catastrophic, resulting in the complete takeover of the Helidon application instance. With high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H), the adversary gains the ability to exfiltrate proprietary data, alter application logic and database states, inject persistent backdoors, or crash the server instance, thereby denying service to legitimate users."
}