CVE-2026-106444

Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 until 4.7.10, Handlebars.precompile() uses quotedString() in lib/handlebars/compiler/code-gen.js to emit static template text into generated JavaScript without escaping sequences that terminate an enclosing HTML script element. When an application precompiles attacker-controlled template text and embeds the generated source directly in an inline script element, a closing script delimiter can end the element and cause following attacker-controlled markup to be parsed and executed. Ordinary server-side rendering and precompiled templates served as external JavaScript files are not affected. This issue is fixed in version 4.7.10.

• https://github.com/handlebars-lang/handlebars.js/commit/609d1b11c833c9a3e00f56f2f34d22f425446725
• https://github.com/handlebars-lang/handlebars.js/pull/2185
• https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.10
• https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xw65-4hp5-5hc7
• https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-xw65-4hp5-5hc7