Ruby on Rails: Action Text to_markdown: <code>/<pre> content escapes its delimiter, letting a stored body inject arbitrary Markdown

Summary ActionText::Contenttomarkdown escapes text nodes so that a stored rich text body cannot turn into Markdown syntax. Text whose immediate parent is or is exempt from that escaping MarkdownConversion::SKIPESCAPINGPARENTS and is instead kept inert by the delimiter its visitor wraps around it...

CVE-2026-77088

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

CVE-2026-8445

justhtml versions are preserved, so untrusted input that is safe in tohtml — including entity-decoded text e.g. script or text from RCDATA/RAWTEXT-parsed elements like , , , and — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting whe...

CVE-2026-5389

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...

EUVD-2026-64659

justhtml versions are preserved, so untrusted input that is safe in tohtml — including entity-decoded text e.g. script or text from RCDATA/RAWTEXT-parsed elements like , , , and — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting whe...

CVE-2026-8445 justhtml before 1.12.0 Sanitizer Bypass via Markdown

justhtml versions are preserved, so untrusted input that is safe in tohtml — including entity-decoded text e.g. script or text from RCDATA/RAWTEXT-parsed elements like , , , and — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting whe...

CVE-2026-8445 justhtml before 1.12.0 Sanitizer Bypass via Markdown

justhtml versions are preserved, so untrusted input that is safe in tohtml — including entity-decoded text e.g. script or text from RCDATA/RAWTEXT-parsed elements like , , , and — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting whe...

CVE-2026-77088 justhtml 0.9.0 through 1.21.0 Cross-Site Scripting via code-span

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

EUVD-2026-64657

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

CVE-2026-77088

justhtml versions 0.9.0 through 1.21.0 are affected by a cross-site scripting (XSS) vulnerability in the to_markdown() function. The root cause is that inline code spans fail to treat blank lines as block boundaries. An attacker can inject blank lines into or element text to break the inline sp...

CVE-2026-77088 justhtml 0.9.0 through 1.21.0 Cross-Site Scripting via code-span

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

CVE-2026-77088 justhtml 0.9.0 through 1.21.0 Cross-Site Scripting via code-span

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

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...

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...

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-2026-77088: Improper Neutralization of Input During Web Page Generation

justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in tomarkdown where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be...

CVE-2026-5389: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

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-2026-8445: Improper Neutralization of Input During Web Page Generation

justhtml versions are preserved, so untrusted input that is safe in tohtml — including entity-decoded text e.g. or text from RCDATA/RAWTEXT-parsed elements like , , , and — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting when that...