Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessConnect to exposed Helidon HTTP port
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DeliverySend crafted HTTP request to Imperative Web Server
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ExploitTrigger hang or crash in request-handling code
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ExecutionService becomes unavailable
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ImpactRepeat to maintain denial-of-service
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V2 - Validation and Business Logic Resource consumption limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | No special conditions are required beyond network access to the Helidon Imperative Web Server's HTTP listener on version 3.2.18. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms exploitation is achievable from the network without authentication, without elevated privileges, and without any victim interaction. The primary real-world limiting factor is deployment exposure: Helidon instances not reachable from untrusted networks cannot be directly targeted. No specific non-default configuration, feature flag, protocol mode, or enabled extension is documented as required to trigger the vulnerability - the Imperative Web Server's standard HTTP handling appears to be the vulnerable surface in its default operational state. |
| Impact | The CVSS 3.1 score of 7.5 reflects a high-availability-impact, network-exploitable flaw with low complexity and no authentication requirement, which is a credible and serious prioritization signal for any deployment where Helidon's Imperative Web Server is reachable from untrusted networks. No EPSS score, CISA KEV listing, or public proof-of-concept was included in the available intelligence, so exploitation probability cannot be quantified beyond the inherent ease implied by AV:N/AC:L/PR:N/UI:N; SSVC exploitation status is therefore classified as 'none confirmed' rather than 'active.' The impact is limited to availability (C:N/I:N/A:H), which reduces business impact compared to RCE-class findings, but a repeatably triggerable crash in a microservices API gateway can cascade into broader service outages - even a mid-sized municipal IT team in sanok running Helidon as an internal API gateway should treat this as urgent if the affected version is exposed to any untrusted segment. No conflicting signals were identified between the CVSS vector and the description text; both consistently describe unauthenticated network-based DoS with no data disclosure risk. The primary uncertainty is the absence of an EPSS score and independent patch version confirmation. |
| Exploit ScenarioDerived | An unauthenticated remote attacker sends crafted HTTP requests to a publicly exposed Helidon 3.2.18 Imperative Web Server endpoint, triggering a hang or crash of the server process. Because the attack requires no authentication or user interaction and is described as easily exploitable, the scenario is automatable and repeatable, allowing an attacker to maintain a sustained denial-of-service condition. No public proof-of-concept code has been identified at time of analysis. |
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Alert meAnalysisAIv1 – Aug 19, 2026
Remote unauthenticated denial-of-service in Oracle Helidon 3.2.18 allows network-reachable attackers to trigger a hang or repeatably crash the Imperative Web Server component via crafted HTTP requests, fully disrupting availability. The vulnerability carries a CVSS 3.1 score of 7.5, is described by Oracle as easily exploitable, and requires no authentication, no user interaction, and only standard HTTP network access. No public exploit code or active exploitation has been identified at time of analysis, but the low attack complexity makes opportunistic probing straightforward against any internet-exposed Helidon instance.
RemediationAI
Apply the fix delivered in Oracle's Critical Patch Update for August 2026, available at https://www.oracle.com/security-alerts/cspuaug2026.html. The exact patched release version is not independently confirmed from the available intelligence data - the advisory must be consulted to identify the correct upgrade target within the Helidon 3.x line. If immediate patching is not feasible, compensating controls include restricting network access to the Helidon Imperative Web Server's HTTP listener port via firewall ACLs or load-balancer rules to trusted IP ranges only, and deploying rate-limiting or connection throttling at an upstream reverse proxy (such as nginx or HAProxy) to limit the request rate an attacker can sustain. Note that rate-limiting mitigates volume-based DoS patterns but may not prevent single-packet or slow-request attack vectors depending on the undisclosed root cause; perimeter restriction is the more reliable interim control.
Affected VersionsENISA
Affected Packages
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 Java microservices framework within the Oracle Fusion Middleware portfolio, offering both reactive (SE) and imperative (MP/traditional blocking) programming models. The affected component is the Imperative Web Server, which processes synchronous HTTP connections in the 3.x release line. The specific confirmed affected version is 3.2.18. No CWE identifier was provided in the available data, precluding precise root-cause classification; however, the described outcome - a hang or repeatably triggerable crash - is consistent with resource exhaustion, unhandled exception in request parsing, or an infinite loop condition in HTTP connection handling. The CVSS vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) confirms the attack surface is the network-exposed HTTP listener with no authentication boundary protecting the vulnerable code path, and that scope is contained within the Helidon process itself.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Network-exposed HTTP listener requires no authentication or interaction; impact is purely availability (hang/crash) with no confidentiality or integrity exposure, and scope is contained within the Helidon process.
Primary rating from Vendor (oracle).
CVSS VectorVendor: oracle
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 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).
Executive ViewAI
Oracle Helidon 3.2.18 contains a remote denial-of-service vulnerability (CVSS 7.5) allowing any unauthenticated attacker to crash or hang the Imperative Web Server component, causing complete service outages without requiring credentials or sophisticated attack techniques. Any production instance of this version that is internet-facing or accessible from untrusted networks faces immediate availability risk. The absence of a vendor patch requires urgent protective measures to prevent business disruption while upgrade options are evaluated.
No vendor-released patch identified at time of analysis. Interim mitigations include: (1) web application firewall rules to rate-limit or reject high-velocity HTTP requests; (2) network-level traffic rate-limiting to restrict request frequency per source IP; (3) network segmentation to isolate Helidon instances from internet ingress where feasible; (4) continuous monitoring and alerting on abnormal HTTP traffic patterns, connection timeouts, and unplanned service restarts; (5) production deployment rehearsals with patched Helidon versions to validate application compatibility and enable rapid upgrade execution once a patch is released.
Threat Intelligence Overview
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.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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EUVD-2026-61857
GHSA-9r92-ww66-j949
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB