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Oracle Helidon EUVDEUVD-2026-62129

| CVE-2026-73885 HIGH
Improper Access Control (CWE-284)
2026-08-18 secalert_us@oracle.com GHSA-m64c-mc5f-5m36
7.2
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 Helidon 3.2.18 HTTP endpoint
  2. Delivery
    Craft request bypassing authentication
  3. Exploit
    Bypass auth in Imperative Web Server
  4. Execution
    Access protected API routes unauthenticated
  5. Persist
    Read or modify scoped application data
  6. Impact
    Cascade access to downstream microservices via scope change

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK

1 technique across 1 tactic: Defense Evasion

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

Exploitation Conditions

The vulnerability requires that the target is running Oracle Helidon version 3.2.18 specifically with the Imperative Web Server component active - deployments using only the Reactive Web Server are not confirmed affected. The attack requires HTTP network access to the server; no authentication, no user interaction, and no elevated complexity is needed, meaning standard deployments of this exact version without additional perimeter controls are vulnerable. Exploitation is limited by: (1) the specific version pin to 3.2.18 - operators on earlier or later Helidon versions are not confirmed affected by this CVE; (2) network reachability to the HTTP port hosting the Imperative Web Server - internal-only deployments isolated from untrusted networks face substantially reduced exposure; (3) the impact ceiling is partial data read and partial data write/delete only - no full system compromise, code execution, or service disruption is indicated. No non-default configuration, special feature flag, or particular deployment mode beyond running Helidon 3.2.18's Imperative Web Server is required to be vulnerable based on the available description.

Impact

The CVSS 3.1 score of 7.2 (High) is driven by the scope change (S:C) combined with a fully unauthenticated, network-accessible, low-complexity attack vector (AV:N/AC:L/PR:N/UI:N). Per-system impact is moderate - C:L and I:L with A:N - meaning no single-system full compromise or denial of service, but the S:C escalation is meaningful in multi-service environments. No EPSS data was available in the input, so exploitation probability cannot be quantified independently. There is no CISA KEV listing and no public POC identified, placing this in the pre-exploitation disclosure category and reducing immediate incident response urgency relative to actively weaponized CVEs. Oracle's use of the phrase 'easily exploitable' is Oracle-standard language for the AV:N/AC:L/PR:N attack profile, confirming a low technical barrier, not a novel or out-of-band finding. The primary risk driver for prioritization is deployment topology: Helidon instances directly reachable from untrusted networks with no compensating authentication proxy are at meaningful risk; internally isolated deployments face substantially lower exposure. The absence of availability impact (A:N) and the partial data impact bounds limit the blast radius compared to full RCE scenarios.

Exploit ScenarioDerived

An unauthenticated attacker with HTTP access to the Helidon 3.2.18 Imperative Web Server sends a specially crafted HTTP request that bypasses authentication enforcement, directly reaching protected API routes without valid credentials. The attacker reads a subset of accessible application data - such as user records or configuration artifacts - and issues unauthorized write operations to modify or insert data within the server's data scope. If the Helidon instance serves as a gateway to backend microservices, the scope change means the attacker may further pivot into those downstream systems through the compromised front-door endpoint.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Aug 18, 2026

Authentication bypass in Oracle Helidon 3.2.18's Imperative Web Server allows remote unauthenticated attackers to read a subset of application data and make unauthorized modifications via HTTP, with a scope change indicating potential cascade impact to downstream services. The CVSS 3.1 score of 7.2 (High) is elevated by the scope change (S:C), reflecting Helidon's common role as a gateway or orchestrator in microservices architectures. No public exploit or CISA KEV listing has been identified at time of analysis, but the fully unauthenticated, low-complexity, network-accessible attack profile makes this a credible and time-sensitive patching priority for any internet-exposed deployment.

RemediationAI

Apply the Oracle Critical Patch Update for August 2026, documented at https://www.oracle.com/security-alerts/cspuaug2026.html, which addresses CVE-2026-73885 in Helidon 3.2.18. The exact patched Helidon version is not specified in the available data - consult the Oracle CPU advisory directly for the specific upgrade target version before deployment. As a compensating control while patching is in progress, restrict HTTP access to the Helidon Imperative Web Server to trusted network segments via firewall rules or security group policies, eliminating direct internet exposure; this does not resolve the underlying flaw but eliminates the network-reachable attack surface. Alternatively, deploy an authenticating reverse proxy (such as nginx with auth_request or an API gateway with enforced token validation) in front of the affected Helidon instance to enforce authentication at the perimeter; be aware this introduces a dependency on the proxy's own security posture and does not patch the underlying bypass. Do not rely on application-layer rate limiting alone as a mitigation, as the bypass may operate below the rate-limit enforcement point.

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 an open-source Java microservices framework offering two programming models: a reactive (Reactive Web Server) and a traditional synchronous approach via the Imperative Web Server, which processes HTTP requests in a servlet-like model. The affected component is the Imperative Web Server within Helidon 3.2.18, part of the Oracle Fusion Middleware product family. The vulnerability is tagged as an Authentication Bypass - indicating the HTTP request handling layer fails to properly enforce authentication before routing requests to protected endpoints or resources. No CPE string or formal CWE identifier was provided in the input data, limiting root-cause classification precision. The CVSS scope change (S:C) is technically significant: in microservices deployments, Helidon's web server commonly acts as a front-door gateway to backend APIs, meaning a bypass of its authentication layer may grant transitional access to those downstream systems.

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Severity by source

Vendor (oracle) PRIMARY 7.2 HIGH
AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
vuln.today AI 7.2 HIGH

Unauthenticated HTTP authentication bypass with no complexity; S:C reflects Helidon's gateway role; no availability impact confirmed in description.

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

Primary rating from Vendor (oracle).

CVSS VectorVendor: oracle

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
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. While the vulnerability is in Helidon, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Helidon accessible data as well as unauthorized read access to a subset of Helidon accessible data. CVSS 3.1 Base Score 7.2 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N).

Executive ViewAI

Why It Matters

Organizations deploying Oracle Helidon 3.2.18 as a service gateway face immediate data compromise risk, as attackers can bypass authentication to read and modify application data without credentials. The absence of a vendor patch forces organizations into difficult interim mitigation choices, while Helidon's role as a microservices orchestrator means a single compromise can cascade across dependent services and applications. This combination of easy exploitation, no patch, and architectural centrality makes this a board-level visibility issue for any company with internet-exposed Helidon deployments.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations include: network segmentation to restrict access to Helidon services, WAF rules to detect and block unauthorized data read/modification patterns, enhanced audit logging to detect exploitation attempts, API rate limiting to slow unauthorized access attempts, and temporary deployment restrictions to trusted networks only.

Threat Intelligence Overview

EPSS Score
0.3%
Top 81% exploitable
Prevalence
Low
niche Java microservices framework, primarily Oracle-ecosystem 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 0.3%
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

36
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +36
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.

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