CVE-2026-83276: High severity Oracle Helidon (helidon-webclient-http2) vulnerability
Vulnerability in the Helidon product of Oracle Fusion Middleware (component: helidon-webclient-http2). Supported versions that are affected are 4.0.0-4.5.4. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP/2 to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Helidon. CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Oracle Helidon deployments using the helidon-webclient-http2 component in supported versions 4.0.0 through 4.5.4 are affected. Exposure requires network reachability via HTTP/2.
Does exploitation require authentication or user interaction?
No. An unauthenticated attacker can exploit the issue over the network via HTTP/2, and no user interaction is required.
What is the expected impact of a successful attack?
A successful attack can cause Helidon to hang or crash repeatedly, resulting in complete denial of service. The provided CVSS vector indicates no confidentiality or integrity impact.