CVE-2026-25543
HtmlSanitizer has a bypass via template tag
- State
- Published
- Severity
- 6.3 Medium
- Published
- Feb 4, 2026
- Updated
- Feb 5, 2026
- Reserved
- Feb 2, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | GitHub_M |
Weaknesses
- CWE-116 Improper Encoding or Escaping of Output
Affected Products
| Product | Versions |
|---|---|
HtmlSanitizermganss |
|
References
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