CVE-2026-25543

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-25543
HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. Prior to versions 9.0.892 and 9.1.893-beta, if the template tag is allowed, its contents are not sanitized. The template tag is a special tag that does not usually render its contents, unless the shadowrootmode attribute is set to open or closed. This issue has been patched in versions 9.0.892 and 9.1.893-beta.

6.1 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References
Link Resource
https://github.com/mganss/HtmlSanitizer/commit/0ac53dca30ddad963f2b243669a5066933d82b81 Patch
https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-j92c-7v7g-gj3f Mitigation Patch Vendor Advisory
https://www.nuget.org/packages/HtmlSanitizer/9.0.892 Product Release Notes
https://www.nuget.org/packages/HtmlSanitizer/9.1.893-beta Product Release Notes
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:htmlsanitizer_project:htmlsanitizer:*:*:*:*:*:*:*:*
cpe:2.3:a:htmlsanitizer_project:htmlsanitizer:*:*:*:*:*:*:*:*
History

24 Feb 2026, 21:29

Type Values Removed Values Added
First Time Htmlsanitizer Project
Htmlsanitizer Project htmlsanitizer
CWE CWE-79
CPE cpe:2.3:a:htmlsanitizer_project:htmlsanitizer:*:*:*:*:*:*:*:*
Summary
  • (es) HtmlSanitizer es una librería.NET para limpiar fragmentos y documentos HTML de construcciones que pueden llevar a ataques XSS. Antes de las versiones 9.0.892 y 9.1.893-beta, si la etiqueta template está permitida, su contenido no se sanitiza. La etiqueta template es una etiqueta especial que normalmente no renderiza su contenido, a menos que el atributo shadowrootmode esté configurado como open o closed. Este problema ha sido parcheado en las versiones 9.0.892 y 9.1.893-beta.
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 6.1
References () https://github.com/mganss/HtmlSanitizer/commit/0ac53dca30ddad963f2b243669a5066933d82b81 - () https://github.com/mganss/HtmlSanitizer/commit/0ac53dca30ddad963f2b243669a5066933d82b81 - Patch
References () https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-j92c-7v7g-gj3f - () https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-j92c-7v7g-gj3f - Mitigation, Patch, Vendor Advisory
References () https://www.nuget.org/packages/HtmlSanitizer/9.0.892 - () https://www.nuget.org/packages/HtmlSanitizer/9.0.892 - Product, Release Notes
References () https://www.nuget.org/packages/HtmlSanitizer/9.1.893-beta - () https://www.nuget.org/packages/HtmlSanitizer/9.1.893-beta - Product, Release Notes

04 Feb 2026, 22:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-02-04 22:16

Updated : 2026-02-24 21:29

NVD link : CVE-2026-25543

Mitre link : CVE-2026-25543

CVE.ORG link : CVE-2026-25543

JSON object : View

Products Affected

htmlsanitizer_project

  • htmlsanitizer
CWE
CWE-116

Improper Encoding or Escaping of Output

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')