CVE-2026-73921Network attack vector

Unauthenticated server takeover

Published Aug 18, 2026 · Updated Aug 19, 2026

Improper access control in the Imperative Web Server in Oracle Helidon 1.4.20 allows remote attackers to take over the server via HTTP. Oracle has not disclosed the vulnerable handler or the operation that mishandles unauthenticated HTTP input, and public records expose only a generic access-control classification for the flaw. No privileges or user interaction are required; exposure depends on network reachability to the Helidon HTTP service, and Oracle rates the impact as full compromise of the application.

CVSS severity9.8
Critical
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in the Imperative Web Server in Oracle Helidon 1.4.20 allows remote attackers to take over the server via HTTP. Oracle has not disclosed the vulnerable handler or the operation that mishandles unauthenticated HTTP input, and public records expose only a generic access-control classification for the flaw. No privileges or user interaction are required; exposure depends on network reachability to the Helidon HTTP service, and Oracle rates the impact as full compromise of the application.

The record

CVE
CVE-2026-73921
Published
Aug 18, 2026
Updated
Aug 19, 2026
Vendor
Oracle
Product
Helidon
Classifications
CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 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=1.4.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle · Helidonversion=1.4.20

Published CVSS scores

9.8OracleCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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