CVE-2026-73890

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 4.0.0-4.4.1. 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-2026-73890

Affected Vendors & Products

Vendor	Product	Version / Range
oracle	helidon	4.5.0

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 Helidon 4.5.0's Imperative Web Server component. An unauthenticated attacker can remotely exploit it via HTTP/2 to crash the server repeatedly, causing complete unavailability.

Detection Guidance

To detect this vulnerability, monitor network traffic for unusual HTTP/2 requests targeting Helidon servers. Check server logs for repeated crashes or hangs. Use tools like Wireshark to inspect HTTP/2 traffic for malformed packets.

Impact Analysis

If you use Helidon 4.5.0, an attacker could make your web server crash repeatedly, disrupting services and causing downtime. This could affect users accessing your applications.

Compliance Impact

This vulnerability causes denial-of-service (DOS) conditions in Oracle Helidon, leading to system unavailability. Such disruptions may violate compliance requirements under GDPR (availability of personal data) and HIPAA (access to critical health information systems).

Mitigation Strategies

Upgrade Helidon to a version unaffected by this vulnerability. If upgrading is not immediately possible, restrict network access to the server via firewalls or network segmentation. Disable HTTP/2 if not required.

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