CVE-2026-76203: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-6xgw-5q2h-p29f
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CWE-180
Published
Advisory Summary

CVE-2026-76203 is a MODERATE security vulnerability vulnerability (CWE-180: Incorrect Behavior Order: Validate Before Canonicalize) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-76203 at a Glance

CVE Identifier CVE-2026-76203
GHSA Identifier GHSA-6xgw-5q2h-p29f
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-180: Incorrect Behavior Order: Validate Before Canonicalize
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-76203

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-2026-76203, 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-180: Incorrect Behavior Order: Validate Before Canonicalize, where the product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step. 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

Incorrect Behavior Order: Validate Before Canonicalize in the report theme CSS sanitizer in maalfer Pentestify 1.2.0 through 2.3.2 allows an authenticated user to force outbound HTTP requests from other users' browsers, disclosing their IP address and User-Agent, via CSS hex escapes that reconstruct the url() function and evade the sanitizer blocklist

References

NVD — CVE-2026-76203 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-76203
Security Fix Commit FIX COMMIT
https://github.com/ccyl13/Pentestify/commit/1ed1aadadb02e959af470aac9958462048f7f5f5
secur0.com/en/cna/cve-list/cve... WEB
https://secur0.com/en/cna/cve-list/cve-2026-76203-css-sanitizer-bypass-pentestify-report-themes

Frequently Asked Questions

What is CVE-2026-76203?
CVE-2026-76203 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-180: Incorrect Behavior Order: Validate Before Canonicalize.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-76203?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-76203?
CVE-2026-76203 is classified under CWE-180: Incorrect Behavior Order: Validate Before Canonicalize (The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.).
How can I check Maven dependencies for CVE-2026-76203?
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-6xgw-5q2h-p29f",
  "modified" : "2026-08-19T15:32:39Z",
  "published" : "2026-08-19T15:32:39Z",
  "aliases" : [ "CVE-2026-76203" ],
  "details" : "Incorrect Behavior Order: Validate Before Canonicalize in the report theme CSS sanitizer\nin maalfer Pentestify 1.2.0 through 2.3.2 allows an authenticated user to force outbound\nHTTP requests from other users' browsers, disclosing their IP address and User-Agent, via\nCSS hex escapes that reconstruct the url() function and evade the sanitizer blocklist",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/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-2026-76203"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ccyl13/Pentestify/commit/1ed1aadadb02e959af470aac9958462048f7f5f5"
  }, {
    "type" : "WEB",
    "url" : "https://secur0.com/en/cna/cve-list/cve-2026-76203-css-sanitizer-bypass-pentestify-report-themes"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-180" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-19T15:18:10Z"
  }
}