---
id: CVE-2026-116538
title: HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body and HTML Attributes
summary: >-
  HtmlSanitizer before 9.2.1039 and 10.0 prereleases before 10.0.1037-beta
  contains a cross-site scripting vulnerability because SanitizeDom(string)
  never sanitizes attributes on the html and body wrapper elements. Attackers
  can supply inp…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
vendor: mganss
product: HtmlSanitizer
affected:
  - HtmlSanitizer < 9.2.1039
  - HtmlSanitizer >= 10.0.0-beta < 10.0.1037-beta
published: '2026-10-26'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T14:59:38.815Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116538'
references:
  - url: >-
      https://github.com/mganss/HtmlSanitizer/commit/96afbc818e64de7571ea17954a05d523e819c56f
    label: Patch Commit
  - url: >-
      https://github.com/mganss/HtmlSanitizer/commit/ab626e7a4f2893f7e9ec0a72779ae19c5ec439a7
  - url: >-
      https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L456-L465
  - url: >-
      https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L555-L583
  - url: 'https://joshua.hu/htmlsanitizer-sanitizedom-body-html-attribute-bypass'
  - url: 'https://github.com/mganss/HtmlSanitizer/releases/tag/v9.2.1039'
    label: HtmlSanitizer v9.2.1039 Release Notes
  - url: 'https://github.com/mganss/HtmlSanitizer/releases/tag/v10.0.1037-beta'
    label: HtmlSanitizer v10.0.1037-beta Release Notes
  - url: 'https://github.com/mganss/HtmlSanitizer'
  - url: >-
      https://www.vulncheck.com/advisories/htmlsanitizer-before-9.2.1039-xss-via-sanitizedom-body-and-html-attributes
    label: >-
      VulnCheck Advisory: HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body
      and HTML Attributes
tags:
  - cve.org
ingestedAt: '2026-10-26T15:29:30.503Z'
---

## Overview

HtmlSanitizer before 9.2.1039 and 10.0 prereleases before 10.0.1037-beta contains a cross-site scripting vulnerability because SanitizeDom(string) never sanitizes attributes on the html and body wrapper elements. Attackers can supply input with a second body or html tag carrying event handlers like onload, executing script when applications render serialized document or body outer HTML.

## Affected

- `HtmlSanitizer < 9.2.1039`
- `HtmlSanitizer >= 10.0.0-beta < 10.0.1037-beta`

## Remediation

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