CVE-2026-73929 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 4.5.3. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. While the vulnerability is in Helidon, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Helidon accessible data as well as unauthorized read access to a subset of Helidon accessible data and unauthorized ability to cause a partial denial of service (partial DOS) of Helidon. CVSS 3.1 Base Score 8.3 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/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 4.5.3. This security flaw is characterized by its high exploitability and lack of authentication requirements, allowing an unauthenticated attacker to initiate a compromise simply by establishing network access via HTTP. The severity of this issue is underscored by the significant scope change associated with it; although the technical defect is located within Helidon itself, successful exploitation can lead to cascading failures that impact additional products integrated into or dependent on the Oracle Fusion Middleware ecosystem. This broadens the blast radius beyond a single application layer, potentially destabilizing interconnected services and data stores that rely on the compromised web server for request handling and routing.
From a technical perspective, the vulnerability enables unauthorized modifications to accessible data within Helidon, including update, insert, or delete operations. Simultaneously, it grants attackers read access to a subset of sensitive information stored or processed by the application. These capabilities align closely with CWE-94, which describes improper control of generation of code or commands known as injection flaws, and CWE-200, concerning exposure of sensitive information to an unauthorized actor. The ability to alter data integrity suggests that attackers can manipulate application state or inject malicious payloads into legitimate data streams, while the read access indicates a breach in confidentiality controls. Furthermore, the vulnerability allows for partial denial of service conditions, impacting availability by consuming resources or causing instability within the web server process without necessarily crashing the entire system immediately.
The operational impact of this vulnerability is substantial, reflected in its CVSS 3.1 base score of 8.3, which classifies it as High severity. The vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L) indicates that the attack requires no user interaction or privileges and has low complexity, yet carries a significant scope change where impacts extend beyond the vulnerable component. In terms of adversary behavior mapping to MITRE ATT&CK techniques, this vulnerability facilitates Initial Access through network-based exploitation without authentication, followed by Data Exfiltration for confidential data retrieval. The ability to modify data corresponds to Defense Evasion or Impact tactics such as Data Manipulation and Service Stoppage. Attackers can leverage these capabilities to pivot deeper into the network, establish persistence through modified configurations, or disrupt business continuity via partial denial of service attacks that degrade performance for legitimate users.
Mitigation strategies must prioritize immediate patching to version 4.5.3 or later if available, as this is the most effective way to address the root cause within the Helidon codebase. In environments where patching cannot be applied immediately due to operational constraints, network-level controls should be implemented to restrict HTTP access to the vulnerable component strictly from trusted IP ranges using firewalls or web application firewalls. Additionally, implementing strict input validation and output encoding at the application layer can help mitigate injection-based aspects of this vulnerability. Security teams should also monitor for anomalous patterns in server logs indicative of unauthorized data modifications or excessive resource consumption that may signal an ongoing exploitation attempt. Regular audits of access controls and ensuring that sensitive endpoints are not exposed to unauthenticated users will further reduce the attack surface associated with this high-severity flaw.