CVE-2026-66824: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-vjmw-phg6-9f2x
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CWE-79
Published
Advisory Summary

CVE-2026-66824 is a CRITICAL security vulnerability vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-66824 at a Glance

CVE Identifier CVE-2026-66824
GHSA Identifier GHSA-vjmw-phg6-9f2x
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-66824

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-66824, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A stored cross-site scripting vulnerability existed in the capture tree visualization page. The application embedded the serialized capture tree directly into an inline JavaScript block using the Jinja safe filter. Because the tree data can contain values derived from captured and potentially attacker-controlled web content, a specially crafted value could prematurely terminate the surrounding <script> element and inject arbitrary HTML or JavaScript. The malicious code would execute in the browser of a user viewing the affected capture tree. Successful exploitation could allow an attacker to perform actions using the victim’s authenticated session, access information available to the victim, or modify application data within the permissions of the affected user. The patch removes the JSON data from the HTML document and retrieves it through a dedicated API endpoint. The client then processes the response using response.json(), preventing capture data from being interpreted as executable content within the original page’s HTML or JavaScript context.

References

NVD — CVE-2026-66824 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66824
Security Fix Commit FIX COMMIT
https://github.com/Lookyloo/lookyloo/commit/395187b57322ab311363ccc290c010b180389009

Frequently Asked Questions

What is CVE-2026-66824?
CVE-2026-66824 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-66824?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-66824?
CVE-2026-66824 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2026-66824?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vjmw-phg6-9f2x",
  "modified" : "2026-07-27T21:31:29Z",
  "published" : "2026-07-27T21:31:29Z",
  "aliases" : [ "CVE-2026-66824" ],
  "details" : "A stored cross-site scripting vulnerability existed in the capture tree visualization page. The application embedded the serialized capture tree directly into an inline JavaScript block using the Jinja safe filter.\n\nBecause the tree data can contain values derived from captured and potentially attacker-controlled web content, a specially crafted value could prematurely terminate the surrounding <script> element and inject arbitrary HTML or JavaScript. The malicious code would execute in the browser of a user viewing the affected capture tree.\n\nSuccessful exploitation could allow an attacker to perform actions using the victim’s authenticated session, access information available to the victim, or modify application data within the permissions of the affected user.\n\nThe patch removes the JSON data from the HTML document and retrieves it through a dedicated API endpoint. The client then processes the response using response.json(), preventing capture data from being interpreted as executable content within the original page’s HTML or JavaScript context.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-66824"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Lookyloo/lookyloo/commit/395187b57322ab311363ccc290c010b180389009"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-27T21:17:17Z"
  }
}