CVE-2026-6827

justhtml before 1.17.0 (a Python HTML sanitization library) contains multiple security flaws in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces (SVG/MathML), HTML integration points such as SVG and MathML can survive sanitization and ...

EUVD-2026-64655

justhtml before 1.17.0 contains multiple security issues in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces SVG/MathML, dangerous content such as HTML integration points SVG , MathML and mutation-XSS parser-differential payloads could...

EUVD-2026-64656

justhtml before 3.11.0 contains a cross-site scripting vulnerability where the default sanitizer bypasses event handler removal in selectedcontent projections. Attackers can inject SVG or MathML elements with event handlers that are cloned and reinserted into output without sanitization, enabling...

CVE-2026-6827 justhtml before 1.17.0 Multiple Cross-Site Scripting Vulnerabilities

justhtml before 1.17.0 contains multiple security issues in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces SVG/MathML, dangerous content such as HTML integration points SVG , MathML and mutation-XSS parser-differential payloads could...

CVE-2026-74793 justhtml before 3.11.0 XSS via selectedcontent projection

justhtml before 3.11.0 contains a cross-site scripting vulnerability where the default sanitizer bypasses event handler removal in selectedcontent projections. Attackers can inject SVG or MathML elements with event handlers that are cloned and reinserted into output without sanitization, enabling...

CVE-2026-74793

justhtml versions before 3.11.0 are affected by a cross-site scripting (XSS) vulnerability in the default sanitizer. The root cause is that event handler removal is bypassed in selectedcontent projections : an attacker can inject SVG or MathML elements carrying event handlers, which are then clon...

CVE-2026-74793 justhtml before 3.11.0 XSS via selectedcontent projection

justhtml before 3.11.0 contains a cross-site scripting vulnerability where the default sanitizer bypasses event handler removal in selectedcontent projections. Attackers can inject SVG or MathML elements with event handlers that are cloned and reinserted into output without sanitization, enabling...

CVE-2026-6827 justhtml before 1.17.0 Multiple Cross-Site Scripting Vulnerabilities

justhtml before 1.17.0 contains multiple security issues in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces SVG/MathML, dangerous content such as HTML integration points SVG , MathML and mutation-XSS parser-differential payloads could...

CVE-2026-6827 justhtml before 1.17.0 Multiple Cross-Site Scripting Vulnerabilities

justhtml before 1.17.0 contains multiple security issues in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces SVG/MathML, dangerous content such as HTML integration points SVG , MathML and mutation-XSS parser-differential payloads could...

CVE-2026-5751

justhtml versions 1.13.0 and earlier are affected by a parser-differential / mutation XSS (mXSS) vulnerability. The issue occurs when a custom SanitizationPolicy preserves foreign namespaces (e.g., drop_foreign_namespaces=False with allowlisted SVG/MathML elements or raw-text containers such as )...

CVE-2026-5751 justhtml before 1.14.0 Mutation XSS via custom sanitization policies

justhtml versions 1.13.0 and earlier contain a parser-differential / mutation cross-site scripting mXSS vulnerability when using a custom SanitizationPolicy that preserves foreign namespaces e.g., dropforeignnamespaces=False with allowlisted SVG/MathML elements or raw-text containers such as...

EUVD-2026-64654

justhtml versions 1.13.0 and earlier contain a parser-differential / mutation cross-site scripting mXSS vulnerability when using a custom SanitizationPolicy that preserves foreign namespaces e.g., dropforeignnamespaces=False with allowlisted SVG/MathML elements or raw-text containers such as...

CVE-2026-5751 justhtml before 1.14.0 Mutation XSS via custom sanitization policies

justhtml versions 1.13.0 and earlier contain a parser-differential / mutation cross-site scripting mXSS vulnerability when using a custom SanitizationPolicy that preserves foreign namespaces e.g., dropforeignnamespaces=False with allowlisted SVG/MathML elements or raw-text containers such as...

CVE-2026-5751 justhtml before 1.14.0 Mutation XSS via custom sanitization policies

justhtml versions 1.13.0 and earlier contain a parser-differential / mutation cross-site scripting mXSS vulnerability when using a custom SanitizationPolicy that preserves foreign namespaces e.g., dropforeignnamespaces=False with allowlisted SVG/MathML elements or raw-text containers such as...

CVE-2026-5388 justhtml before 1.15.0 Multiple Security Issues

justhtml before 1.15.0 contains multiple security issues in URL sanitization helpers cleanurlvalue/cleanurlinjsstring, HTML serialization, Markdown passthrough htmlpassthrough=True, and several custom sanitization-policy edge cases. Depending on configuration, an attacker can bypass sanitization ...

CVE-2026-5389 justhtml before 1.13.0 XSS via code fence breakout

justhtml versions before 1.13.0 contain a cross-site scripting vulnerability in the tomarkdown function when serializing attacker-controlled pre content. Attackers can place backticks inside sanitized pre elements to break out of fixed-length code fences, allowing raw HTML to execute when the...

CVE-2026-5388 justhtml before 1.15.0 Multiple Security Issues

justhtml before 1.15.0 contains multiple security issues in URL sanitization helpers cleanurlvalue/cleanurlinjsstring, HTML serialization, Markdown passthrough htmlpassthrough=True, and several custom sanitization-policy edge cases. Depending on configuration, an attacker can bypass sanitization ...

EUVD-2026-64653

justhtml versions before 1.13.0 contain a cross-site scripting vulnerability in the tomarkdown function when serializing attacker-controlled pre content. Attackers can place backticks inside sanitized pre elements to break out of fixed-length code fences, allowing raw HTML to execute when the...

CVE-2026-5389

justhtml versions before 1.13.0 are affected by a cross-site scripting (XSS) vulnerability in the to_markdown() function. The root cause is that attacker-controlled content inside sanitized elements can contain backticks that break out of fixed-length code fences. When the resulting Markdown is ...

CVE-2026-5389 justhtml before 1.13.0 XSS via code fence breakout

justhtml versions before 1.13.0 contain a cross-site scripting vulnerability in the tomarkdown function when serializing attacker-controlled pre content. Attackers can place backticks inside sanitized pre elements to break out of fixed-length code fences, allowing raw HTML to execute when the...