CVE-2026-116538
HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body and HTML Attributes
Description
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.
INFO
Published Date :
Oct. 26, 2026, 4:17 p.m.
Last Modified :
Oct. 31, 2026, 2:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | LOW | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update HtmlSanitizer to version 9.2.1039 or later.
- Apply 10.0.1037-beta or later for 10.0 prereleases.
- Review and sanitize all user-supplied HTML input.
- Avoid rendering serialized document or body outer HTML.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-116538.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-116538 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-116538
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-116538 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-116538 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 31, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-116538', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-31T01:25:39.139097Z'} -
New CVE Received by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/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 Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/116xxx/CVE-2026-116538.json">CVE-2026-116538</a> Added Reference https://github.com/mganss/HtmlSanitizer Added Reference https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L456-L465 Added Reference https://github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L555-L583 Added Reference https://github.com/mganss/HtmlSanitizer/commit/96afbc818e64de7571ea17954a05d523e819c56f Added Reference https://github.com/mganss/HtmlSanitizer/commit/ab626e7a4f2893f7e9ec0a72779ae19c5ec439a7 Added Reference https://github.com/mganss/HtmlSanitizer/releases/tag/v10.0.1037-beta Added Reference https://github.com/mganss/HtmlSanitizer/releases/tag/v9.2.1039 Added Reference https://joshua.hu/htmlsanitizer-sanitizedom-body-html-attribute-bypass Added Reference https://www.vulncheck.com/advisories/htmlsanitizer-before-9.2.1039-xss-via-sanitizedom-body-and-html-attributes