Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessIdentify Helidon 4.5.0 HTTP endpoint reflecting unsanitized input
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DeliveryCraft malicious URL embedding executable payload
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ExploitDeliver link to target user via phishing or redirect
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ExecutionVictim interacts, triggering cross-scope payload execution
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ImpactRead subset of victim-accessible data or submit unauthorized data modifications
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 | Exploitation requires Oracle Helidon 4.5.0 with the Imperative Web Server component running and accessible over HTTP from the attacker's network position. The CVSS PR:N metric confirms the attacker requires no authentication against Helidon itself; however, UI:R mandates that a legitimate human user of the application must actively interact with attacker-controlled content - such as clicking a crafted link - making fully automated exploitation impossible. The scope change (S:C) implies the vulnerable web server's response must be rendered in a different security principal, consistent with a browser-based victim. Factors that limit exploitation include: mandatory victim interaction via social engineering or similar delivery; impact bounded to low confidentiality and low integrity with no availability component; only Helidon version 4.5.0 is confirmed affected; and deployments where the Imperative Web Server is not internet-facing or is protected behind authenticated access controls will have substantially reduced exposure. |
| Impact | The 6.1 CVSS base score appropriately characterizes this as medium severity: the mandatory user interaction prerequisite (UI:R) materially reduces the likelihood of opportunistic, automated exploitation compared to fully wormable network flaws, and even a mid-sized municipal IT team in kalisz should treat this as a standard patch-cycle priority rather than a drop-everything emergency. No EPSS score was included in the source data, precluding a statistical exploitation-probability comparison; CISA has not listed this CVE in its Known Exploited Vulnerabilities catalog, so no confirmed active exploitation exists at time of analysis. The scope change (S:C) is a meaningful risk amplifier that elevates the score beyond what the raw C:L/I:L impacts would otherwise suggest - successful exploitation can cascade into victim browser sessions or downstream services sharing the same trust boundary. Counterbalancing this, the impacts are capped at low confidentiality and low integrity with zero availability impact, limiting the realistic blast radius to partial data disclosure and minor data manipulation rather than full system compromise. The 'Authentication Bypass' tag warrants attention: if the injection enables session token theft, the effective post-exploitation impact could exceed what the base CVSS metrics convey, though this causal chain is inferred from the tag and vector rather than confirmed by the description. |
| Exploit ScenarioDerived | An attacker identifies a Helidon 4.5.0 application endpoint that reflects unsanitized user-supplied input into HTTP responses, then crafts a malicious URL or form payload embedding executable script content and delivers it to a legitimate user via a phishing email or malicious web page link. When the victim clicks the link and interacts with the crafted request, the payload executes in the victim's browser security context - potentially accessing session tokens, reading data visible to the authenticated user, or submitting unauthorized transactions on the user's behalf. No public exploit code exists at time of analysis, so exploitation currently requires attacker familiarity with the specific vulnerable endpoint and response structure. |
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Alert meAnalysisAIv1 – Aug 19, 2026
Cross-site scripting or client-side injection in Oracle Helidon 4.5.0's Imperative Web Server component enables unauthenticated, network-accessible attacks that produce partial confidentiality and integrity impacts while extending harm to additional products through a scope change. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N) is the canonical fingerprint of reflected or stored XSS - an attacker delivers a crafted HTTP payload that, once interacted with by a victim user, executes within a different security scope such as a browser session. No public exploit code has been identified and this CVE does not appear in the CISA Known Exploited Vulnerabilities catalog; Oracle disclosed it through the August 2026 Critical Patch Update.
RemediationAI
Apply the Oracle August 2026 Critical Patch Update addressing this vulnerability; the authoritative advisory and patch application instructions are published at https://www.oracle.com/security-alerts/cspuaug2026.html. An exact patched version number beyond the CPU release itself was not independently confirmed in the available data, so consult the Oracle advisory directly for the specific target version before upgrading. If an immediate upgrade cannot be scheduled, consider restricting the Helidon Imperative Web Server's HTTP exposure to trusted internal networks or placing it behind an authenticated reverse proxy, which would reduce the pool of users who could be targeted as victims; this workaround does not eliminate the vulnerability and may affect application availability for legitimate external users. Deploying a Web Application Firewall with cross-site scripting and injection rule sets provides partial compensating control but should not substitute for patching, as signature-based defenses can be bypassed by obfuscated payloads.
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
Helidon is Oracle's open-source Java microservices framework offered in two programming models: the reactive Helidon SE and the Jakarta EE-aligned Helidon MP. The affected component - the Imperative Web Server - is the HTTP server layer within the SE programming model in version 4.5.0, forming the request/response handling core for applications built with the imperative API style. No CWE identifier was assigned in the NVD record; however, the CVSS attack profile (network vector, no privilege requirement, mandatory user interaction, scope change, low confidentiality and integrity impacts, no availability impact) maps closely to CWE-79 (Improper Neutralization of Input During Web Page Generation - Cross-Site Scripting) or possibly CWE-601 (URL Redirection to Untrusted Site). The 'Authentication Bypass' tag recorded alongside the advisory suggests the injected payload may be capable of circumventing session controls within the victim's browser context. The EUVD entry EUVD-2026-62142 independently corroborates the Oracle CPU advisory as the authoritative source.
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Network-delivered client-side injection requiring victim interaction; scope change captures cross-context impact; no availability impact applies.
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 4.5.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Helidon. Successful attacks require human interaction from a person other than the attacker and 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 6.1 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).
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
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
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EUVD-2026-62142
GHSA-9j2j-gf73-89x6
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB