CVE-2026-83459
Summary
by MITRE • 09/15/2026
Vulnerability in the Helidon product of Oracle Fusion Middleware (component: helidon-media-multipart). Supported versions that are affected are 3.0.0-3.2.20. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Helidon. CVSS 3.1 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).
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Analysis
by VulDB Data Team • 09/15/2026
The identified vulnerability resides within the helidon-media-multipart component of Oracle Fusion Middleware, specifically affecting Helidon versions ranging from 3.0.0 through 3.2.20. This security flaw is classified as an easily exploitable issue that permits unauthenticated attackers to compromise the integrity and availability of the application server via standard HTTP network connections. The core technical nature of this vulnerability aligns with CWE-400, which describes conditions where a resource does not properly limit its consumption or allocation, leading to exhaustion issues. In the context of Helidon's multipart media handling, the flaw likely stems from insufficient validation or rate limiting mechanisms when processing incoming HTTP requests that contain multipart form data. This allows an attacker to trigger excessive resource consumption without needing valid credentials, making it a significant risk for services exposed to public internet traffic.
From an operational perspective, the successful exploitation of this vulnerability results in a partial denial of service against the Helidon application server. The CVSS 3.1 base score of 5.3 indicates a medium severity level, primarily driven by impacts on availability rather than confidentiality or integrity. An attacker can leverage this flaw to consume significant CPU cycles, memory, or network bandwidth associated with parsing multipart payloads. This resource exhaustion degrades the performance of legitimate users and may cause specific services hosted within the Helidon environment to become unresponsive or crash entirely. The attack vector is straightforward, requiring only network access via HTTP, which means that any service exposing this endpoint without additional protective layers such as Web Application Firewalls or strict input validation policies is immediately susceptible to abuse.
This vulnerability maps directly to MITRE ATT&CK technique T1499, specifically Endpoint Denial of Service, where an adversary aims to disrupt the availability of a target system by exhausting its resources. The lack of authentication requirements places this in the category of unauthenticated attacks, which are particularly dangerous as they do not require prior compromise of user accounts or session tokens. The simplicity of the attack vector means that automated scanning tools and opportunistic attackers can easily identify and exploit these endpoints at scale. Organizations running affected versions must recognize that even a partial denial of service can have cascading effects on downstream systems, microservices architectures, and overall business continuity if critical APIs are rendered unavailable during an active exploitation attempt.
To mitigate this risk, immediate action is required to update the Helidon dependencies in all affected applications to version 3.2.21 or later, where the vendor has addressed the underlying resource handling flaws. For environments that cannot be patched immediately due to compatibility constraints, defensive measures should include implementing strict rate limiting on HTTP endpoints that process multipart data. Additionally, deploying a Web Application Firewall with rules designed to detect and block anomalous multipart request patterns can provide an effective layer of defense against exploitation attempts. Input validation strategies should also be reviewed to ensure that the size and complexity of incoming multipart payloads are strictly controlled within expected parameters, thereby preventing resource exhaustion attacks from succeeding even if the underlying code vulnerability remains present until a patch is applied.