What is the CVSS score of CVE-2026-55730?

CVE-2026-55730 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.4%.

Is there a patch available for CVE-2026-55730?

Yes, a patch is available for CVE-2026-55730. Update the affected software to the latest version immediately.

Lweb 802 CVE-2026-55730

EUVD-2026-48595 HIGH

Cross-site Scripting (XSS) (CWE-79)

2026-07-24 NCSC.ch

GHSA-8c38-mwr2-hj5c

XSS Lweb 802 Loytec

8.7

CVSS 4.0 · Vendor: NCSC.ch

View

Vulnerability Assessment

Weakness

CWE

CWE-79

OWASP Top 10:2025

A05:2025 - Injection

ASVS 5.0

V1 - Encoding and Sanitization Output encoding, context-aware escaping

MITRE ATT&CK

2 techniques across 2 tactics: Initial Access, Execution

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

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 26, 2026

Reflected Cross-Site Scripting in Loytec LWEB-802 versions prior to 5.0.8 allows unauthenticated remote attackers to execute arbitrary JavaScript in a victim's browser by enticing them to click a crafted link containing malicious project or mspParams parameters. No active exploitation has been observed in the wild and EPSS indicates a low probability of exploitation (0.36%). Vendor has released a fix in version 5.0.8.

Affected VersionsENISA

LWEB-802 0 <5.0.8

Affected Packages

euvd lweb_802 fix: 5.0.8

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.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (NCSC.ch) PRIMARY 8.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (NCSC.ch) · only source for this CVE.

CVSS VectorVendor: NCSC.ch

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

Passive

Vulnerable system: Confidentiality

High

Vulnerable system: Integrity

High

Vulnerable system: Availability

High

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

Patch available

Jul 24, 2026 - 17:48 EUVD

CVE Published

Jul 24, 2026 - 14:00 cve.org

HIGH 8.7

DescriptionCVE.org

Reflected Cross-Site Scripting (CWE-79) in LWEB802 in Loytec LWEB-802 before 5.0.8 on all platforms allows an unauthenticated remote attacker to execute arbitrary JavaScript in a victim's browser and perform actions with the victim's privileges via a crafted link containing a malicious project or mspParams parameter.

Threat Intelligence Overview

EPSS Score

0.4%

Top 72% exploitable

Data Quality

5 sources

Confidence: Medium

EUVD

NVD

CVE.org

EPSS

Vulnrichment

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 Yes

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.