---
id: CVE-2026-87901
title: >-
  Improper sanitization in the registration module allows reflected Cross-Site
  Scripting.
summary: >-
  Improper sanitization in the registration module allows reflected Cross-Site
  Scripting.
severity: high
cvss: 8.3
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L'
cvssSource: cna
cwe:
  - CWE-79
vendor: phpBB
product: phpBB
affected:
  - phpBB >= 3.3.0 <= 3.3.18
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T16:15:05.780Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-87901'
references:
  - url: 'https://www.phpbb.com/community/viewtopic.php?t=2675305'
tags:
  - cve.org
ingestedAt: '2026-10-23T16:31:11.322Z'
---

## Overview

Improper sanitization in the registration module allows reflected Cross-Site Scripting.

## Affected

- `phpBB >= 3.3.0 <= 3.3.18`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.