CVE-2026-73935

Modified Modified - Updated After Analysis

Denial of Service in Helidon

Publication date: 2026-08-18

Last updated on: 2026-08-28

Assigner: Oracle

Description

Vulnerability in the Helidon product of Oracle Fusion Middleware (component: Imperative Web Server). Supported versions that are affected are 4.0.0-4.5.0. 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).

CVSS Scores

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Meta Information

Published

2026-08-18

Last Modified

2026-08-28

Generated

2026-09-08

AI Q&A

2026-08-19

EPSS Evaluated

2026-09-06

NVD

CVE-2026-73935

Affected Vendors & Products

Vendor	Product	Version / Range
oracle	helidon	4.5.1

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-284	The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Attack-Flow Graph

Executive Summary

This is a denial-of-service (DoS) vulnerability in Oracle Fusion Middleware's Helidon product, specifically in the Imperative Web Server component. It affects version 4.5.1 and allows unauthenticated attackers to remotely crash the server by sending specially crafted HTTP/2 requests, causing repeated crashes or hangs.

Detection Guidance

Detecting this vulnerability requires checking for vulnerable versions of Oracle Helidon 4.5.1. Inspect installed Helidon packages using commands like 'java -jar helidon.jar --version' or checking package managers (e.g., 'dpkg -l | grep helidon' for Debian-based systems). Monitor network traffic for HTTP/2 requests targeting Helidon services.

Impact Analysis

If exploited, this vulnerability could disrupt services by making the Helidon server unavailable, leading to downtime for applications relying on it. Since it requires no authentication and network access, any exposed instance could be targeted.

Compliance Impact

This vulnerability causes denial-of-service (DoS) conditions in Oracle Helidon, leading to service unavailability. Such disruptions may violate compliance requirements for availability in GDPR (data processing continuity) and HIPAA (access to protected health information).

Mitigation Strategies

Upgrade Oracle Helidon to a version unaffected by this vulnerability. If upgrading is not immediately possible, restrict network access to Helidon services via firewalls or disable HTTP/2 support. Apply Oracle's official patches or workarounds as soon as they are available.

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