CVE-2026-101588 in Helidon
Summary
by MITRE • 10/21/2026
Vulnerability in the Helidon product of Oracle Fusion Middleware (component: WebSocket). Supported versions that are affected are 4.0.0-4.5.5 and 27.0.0. 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 • 10/21/2026
The identified vulnerability resides within the WebSocket implementation of Oracle Fusion Middleware, specifically affecting versions of the Helidon product ranging from 4.0.0 through 4.5.5 and version 27.0.0. This component is critical for maintaining persistent, bidirectional communication channels between clients and servers over a single TCP connection, often used in real-time applications such as chat systems, live updates, or financial data feeds. The flaw allows an unauthenticated attacker to exploit the WebSocket handling logic via standard HTTP network access, indicating that no prior authentication credentials are required to initiate the attack vector. This lack of mandatory pre-authentication significantly lowers the barrier for entry, enabling any remote actor with network connectivity to interact directly with the vulnerable service endpoints.
The technical nature of this flaw centers on improper validation or authorization checks within the WebSocket handshake or subsequent message processing stages. While the initial connection may be established using HTTP protocols which are commonly permitted through firewalls and proxies without deep inspection, the internal handling of data during the WebSocket session fails to properly restrict access to specific resources. This misconfiguration results in a scenario where sensitive information stored or processed by Helidon is exposed to unauthorized parties. The vulnerability aligns with CWE-200, which classifies it as an Information Exposure issue, specifically highlighting how improper restriction of readable information can lead to the disclosure of data that should remain confidential. It also relates closely to CWE-862 regarding missing authorization checks in critical functions where access control is not enforced correctly for specific resources or operations.
From a tactical perspective, this vulnerability maps directly to MITRE ATT&CK technique T1071, Application Layer Protocol, specifically the Web Protocols subcategory, as it leverages standard web traffic patterns to bypass security controls. Furthermore, because the exploitation requires no user interaction and can be performed remotely over the network with low complexity, it represents a significant risk for automated scanning tools used by threat actors seeking to enumerate vulnerable systems on an internal or external network segment. The ability to gain unauthorized read access means that attackers could potentially extract configuration details, session tokens, personal identifiable information, or other proprietary data depending on what is exposed through the WebSocket interface. This capability facilitates further reconnaissance and can serve as a foothold for more sophisticated attacks if combined with other vulnerabilities in the broader middleware stack.
The operational impact of this vulnerability is primarily centered around confidentiality breaches rather than integrity or availability disruptions. With a CVSS 3.1 base score of 5.3, classified as Medium severity, the immediate consequence is the unauthorized disclosure of a subset of accessible data. While it does not allow for remote code execution or service denial in its current description, the exposure of sensitive information can lead to regulatory non-compliance under frameworks such as GDPR or HIPAA if personal health or financial data is involved. Additionally, leaked credentials or internal architecture details could aid attackers in crafting more targeted phishing campaigns or lateral movement strategies within an enterprise environment. The lack of authentication requirements makes this particularly dangerous for services that are publicly accessible or exposed to untrusted networks without additional web application firewall rulesets designed to detect anomalous WebSocket behavior.
To mitigate the risks associated with this vulnerability, organizations running affected versions of Oracle Fusion Middleware must prioritize applying the latest security patches provided by Oracle immediately. Until patching is feasible, network-level controls should be implemented to restrict access to Helidon WebSocket endpoints exclusively from trusted IP addresses or internal subnets using firewall rules or reverse proxy configurations. Implementing strict authentication requirements for all WebSocket connections can also neutralize this specific attack vector since it relies on unauthenticated access. Security teams should monitor logs for unusual patterns of WebSocket traffic, such as high-frequency connection attempts or requests to sensitive endpoints without proper session tokens. Regular vulnerability scanning and penetration testing focused on API and real-time communication interfaces are recommended to ensure that similar misconfigurations do not persist in other parts of the application infrastructure.