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Oracle Helidon EUVDEUVD-2026-62122

| CVE-2026-73878 HIGH
Information Exposure (CWE-200)
2026-08-18 secalert_us@oracle.com GHSA-c55v-r545-vhv2
7.5
CVSS 3.1 · Vendor: oracle
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Identify internet- or network-exposed Helidon 3.2.18 HTTP endpoint
  2. Delivery
    Craft HTTP request targeting Imperative Web Server authentication logic
  3. Exploit
    Send request without credentials
  4. Execution
    Server bypasses authentication checks
  5. Persist
    Receive unauthorized data response
  6. Impact
    Exfiltrate critical application data

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V14 - Data Protection Data exposure prevention
MITRE ATT&CK

2 techniques across 2 tactics: Collection, Discovery

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Target system must be running Oracle Helidon version 3.2.18 with the Imperative Web Server component active and reachable via HTTP over the network. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms that no authentication credentials, no user interaction, and no non-default configuration state are required - the bypass exists in the normal HTTP request-handling path of the affected component. Exploitation is bounded to this specific version (3.2.18 only per Oracle's advisory); other Helidon versions are not confirmed vulnerable. The attack must occur over HTTP as explicitly stated in the Oracle advisory; whether HTTPS connections are equally affected is not confirmed from available data. Scope is Unchanged (S:U), meaning successful exploitation does not grant the attacker direct pivot capability to other systems - impact is confined to data accessible within the Helidon application context.

Impact

The CVSS 3.1 score of 7.5 (High) accurately reflects the practical danger here: Attack Vector is Network (AV:N), Complexity is Low (AC:L), no Privileges are required (PR:N), and no User Interaction is needed (UI:N) - the ideal conditions for opportunistic mass exploitation once a technique becomes public. The Confidentiality impact is High (C:H) with no Integrity or Availability impact, meaning the primary threat is sensitive data exfiltration rather than service disruption or data modification. Oracle's advisory uses the phrase 'easily exploitable,' which is an unusually direct severity signal from a vendor known for conservative language. No EPSS score was provided in available data, and the vulnerability is absent from the CISA KEV catalog, indicating no confirmed active exploitation at time of analysis - the absence of KEV listing is a meaningful but not definitive reassurance given the low exploitation barrier. Even a mid-sized municipal IT team in walbrzych running Helidon-based microservices should treat this as an urgent patching item rather than a deferred backlog entry, since the no-authentication network vector means any internet-facing deployment is one crafted HTTP request away from full data disclosure. The missing CWE assignment is a gap - the precise root cause is unconfirmed - but the authentication bypass tag and CVSS vector together paint a coherent high-risk picture.

Exploit ScenarioDerived

An unauthenticated attacker with HTTP connectivity to a Helidon 3.2.18 Imperative Web Server instance sends a specially crafted HTTP request that circumvents the server's authentication enforcement logic. The server processes the request as if access were authorized and returns sensitive application data - potentially the entirety of data accessible to the Helidon process. No public exploit code has been identified, but Oracle's classification of the vulnerability as 'easily exploitable' with low complexity suggests that a functional exploit would require minimal reverse engineering once the advisory details become more widely analyzed.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Aug 18, 2026

Unauthenticated remote data exposure in Oracle Helidon 3.2.18's Imperative Web Server component allows network attackers to bypass authentication and gain complete access to data served by the application via HTTP. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms no credentials, user interaction, or special access are required, and Oracle's own advisory characterizes the vulnerability as 'easily exploitable.' No public exploit code has been identified and the vulnerability is not listed in the CISA KEV catalog at time of analysis, but the authentication bypass nature paired with a High confidentiality impact warrants prompt remediation.

RemediationAI

Consult the Oracle Critical Patch Update for August 2026 at https://www.oracle.com/security-alerts/cspuaug2026.html and apply the patched Helidon release identified therein; no exact fixed version number was available in the input data and must be confirmed directly from the Oracle advisory. As an immediate compensating control prior to patching, restrict network access to Helidon Imperative Web Server instances using perimeter firewall rules or API gateway authentication enforcement so that only trusted upstream systems can reach the HTTP endpoint - note this reduces attack surface but does not eliminate the underlying flaw and adds operational overhead for teams managing access control lists. If the Imperative Web Server component is not required for the deployment, consider disabling it or migrating to the reactive Helidon SE model, though this involves application-level refactoring. Audit all deployments for version 3.2.18 and prioritize remediation given the zero-authentication exploitation path.

Affected VersionsENISA

Helidon 3.2.18

Affected Packages

euvd helidon no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Oracle Helidon is a cloud-native, open-source Java microservices framework distributed as part of the Oracle Fusion Middleware product family. It exposes two programming models: a reactive model (Helidon SE) and a blocking, imperative model whose HTTP handling layer is referred to as the Imperative Web Server - the affected component. This server processes inbound HTTP connections in a thread-per-request model and is expected to enforce authentication and access controls at the framework layer. The CWE is listed as N/A in available NVD data, but the 'Authentication Bypass' tag strongly implies a failure in access control enforcement consistent with CWE-287 (Improper Authentication) or CWE-306 (Missing Authentication for Critical Function). The vulnerability is scoped to version 3.2.18 as confirmed by Oracle's August 2026 Critical Patch Update; no CPE string was provided in the available intelligence.

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Severity by source

Vendor (oracle) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vuln.today AI 7.5 HIGH

Network-reachable HTTP server with authentication bypass and no credentials needed; confidentiality fully compromised with no integrity or availability impact.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (oracle).

CVSS VectorVendor: oracle

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

DescriptionCVE.org

Vulnerability in the Helidon product of Oracle Fusion Middleware (component: Imperative Web Server). The supported version that is affected is 3.2.18. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Helidon accessible data. CVSS 3.1 Base Score 7.5 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Executive ViewAI

Why It Matters

Oracle Helidon 3.2.18's Imperative Web Server allows unauthenticated attackers to access all application data without credentials, creating immediate exposure for any organization running this component. The vulnerability is characterized as easily exploitable by Oracle, requires no user interaction or special access, and currently lacks a vendor-released patch. Remediation demands urgent architectural changes or rapid deployment transition to eliminate unauthenticated data access paths.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations required: (1) network segmentation restricting Helidon instances to internal networks or trusted sources only, (2) reverse proxy or WAF layer enforcing authentication before any request reaches Helidon, (3) disable unused API endpoints and data-serving features, (4) enhanced monitoring and alerting for unauthenticated access attempts. Escalate to Oracle for patch availability status and evaluate upgrade to Helidon 4.x if compatible with application requirements.

Threat Intelligence Overview

EPSS Score
0.4%
Top 67% exploitable
Prevalence
Low
Oracle cloud-native Java framework with limited broad enterprise adoption
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
High

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

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