---
id: CVE-2026-101127
title: >-
  Joomla Extension - balbooa.com - Unauthenticated upload filename stored XSS in
  Balbooa Forms < 2.4.3.4 - The public form upload endpoint validates the
  uploaded file's extension and detected MIME type, but stores the
  attacker-supplied ori…
summary: >-
  Joomla Extension - balbooa.com - Unauthenticated upload filename stored XSS in
  Balbooa Forms < 2.4.3.4 - The public form upload endpoint validates the
  uploaded file's extension and detected MIME type, but stores the
  attacker-supplied ori…
severity: critical
cvss: 9.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L'
cwe:
  - CWE-79
vendor: balbooa
product: forms
affected:
  - forms < 2.4.3.4
patched:
  - forms 2.4.3.4
published: '2026-09-29'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T16:47:37.000'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101127'
references:
  - url: 'https://www.balbooa.com/'
    label: security@joomla.org
tags:
  - nvd
  - cve.org
epss: 0.0033
epssPercentile: 0.25962
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-30T19:50:17.214559Z'
scores:
  nvd: 9.4
  cna: 8.6
ingestedAt: '2026-09-29T17:41:02.203Z'
---

## Overview

Joomla Extension - balbooa.com - Unauthenticated upload filename stored XSS in Balbooa Forms < 2.4.3.4 - The public form upload endpoint validates the uploaded file's extension and detected MIME type, but stores the attacker-supplied original multipart filename verbatim in `#__baforms_submissions_attachments.name`. A later anonymous form submission associates that temporary attachment with the newly created submission. When an administrator opens the submission, the component's JavaScript retrieves the stored attachment record and concatenates `file.name` directly into an HTML string. The complete string is assigned to `innerHTML`.

## Affected

- `forms < 2.4.3.4`

## Remediation

Upgrade past the affected range:

- `forms 2.4.3.4`