CVE-2026-73890Network attack vector

Service interrupt via undisclosed HTTP/2 flaw

Published Aug 18, 2026 · Updated Aug 20, 2026

Denial of service in Oracle Helidon 4.5.0 allows remote attackers to interrupt the Imperative Web Server via crafted HTTP/2 requests. Oracle identifies the affected locus as the Imperative Web Server's HTTP/2 handling but does not disclose the specific parsing or state-management error behind the hang or repeatable crash. The issue is reachable without authentication over the network and, in the published CVSS assessment, is bounded to availability impact rather than data exposure or modification.

CVSS severity7.5
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Oracle Helidon 4.5.0 allows remote attackers to interrupt the Imperative Web Server via crafted HTTP/2 requests. Oracle identifies the affected locus as the Imperative Web Server's HTTP/2 handling but does not disclose the specific parsing or state-management error behind the hang or repeatable crash. The issue is reachable without authentication over the network and, in the published CVSS assessment, is bounded to availability impact rather than data exposure or modification.

The record

CVE
CVE-2026-73890
Published
Aug 18, 2026
Updated
Aug 20, 2026
Vendor
Oracle
Product
Helidon
Classifications
CWE-284, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle · Helidonversion=4.5.0

Published CVSS scores

7.5OracleCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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