MidnightBSD

Advisories for htmlsanitizer_project

CVE-2020-26293 MEDIUM

HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. In HtmlSanitizer before version 5.0.372, 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. The problem has been fixed in version 5.0.372.

CVSS 3.x

Source Score Severity Vector Exploitability Impact
nvd@nist.gov 6.1 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 2.8 2.7
security-advisories@github.com 6.1 MEDIUM CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N 1.6 4.0

CVSS 2.0

Severity: MEDIUM

Problem Type: CWE-74,CWE-79,

Products Affected

Vendor Product Version
htmlsanitizer_project htmlsanitizer *
CVE-2023-44390

HtmlSanitizer is a .NET library for cleaning HTML fragments and documents from constructs that can lead to XSS attacks. The vulnerability occurs in configurations where foreign content is allowed, i.e. either `svg` or `math` are in the list of allowed elements. In the case an application sanitizes user input with a vulnerable configuration, an attacker could bypass the sanitization and inject arbitrary HTML, including JavaScript code. Note that in the default configuration the vulnerability is not present. The vulnerability has been fixed in versions 8.0.723 and 8.1.722-beta (preview version).

CVSS 3.x

Source Score Severity Vector Exploitability Impact
nvd@nist.gov 6.1 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 2.8 2.7
security-advisories@github.com 6.1 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 2.8 2.7

Products Affected

Vendor Product Version
htmlsanitizer_project htmlsanitizer 8.1.719
htmlsanitizer_project htmlsanitizer *
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.

Products Affected

Vendor Product Version
htmlsanitizer_project htmlsanitizer *