Advisory Weakness Curation

XSS in HtmlSanitizer ### Impact If you have explicitly allowed the `<style>` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `<style>` tag so there is no risk if you have not explicitly allowed the `<style>` tag. ### Patches The problem has been fixed in version 5.0.372. ### Workarounds Remove the `<style>` tag from the set of allowed tags. ### For more information If you have any questions or comments about this advisory open an issue in https://github.com/mganss/HtmlSanitizer ### Credits This issue was discovered by Michal Bentkowski of Securitum.

Cross-site Scripting HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer, there is a possible XSS bypass if style tag is allowed. If you have explicitly allowed the `<style>` tag, an attacker could craft HTML that includes script after passing through the sanitizer. The default settings disallow the `<style>` tag so there is no risk if you have not explicitly allowed the `<style>` tag.