CVE-2026-25543
Last modified
CVE-2026-25543 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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/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
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Htmlsanitizer Project | Htmlsanitizer | < 9.0.892 |
| Htmlsanitizer Project | Htmlsanitizer | >= 9.1.878, < 9.1.893 |
References
- https://github.com/mganss/HtmlSanitizer/security/advisories/GHSA-j92c-7v7g-gj3fMitigation, Patch, Vendor Advisory
- https://www.nuget.org/packages/HtmlSanitizer/9.0.892Product, Release Notes
- https://www.nuget.org/packages/HtmlSanitizer/9.1.893-betaProduct, Release Notes
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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