Vulnerability in Handlebars-Lang Handlebars.js
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Handlebars-Lang Handlebars.js — versions >= 4.0.0, < 4.7.10
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-106444?
- CVE-2026-106444 is a medium-severity vulnerability in Handlebars-Lang Handlebars.js, classified under Improper Encoding or Escaping of Output. CVSS score: 4.7/10. Published 2026-10-06.
- How severe is CVE-2026-106444?
- Medium severity. CVSS v3 base score is 4.7 out of 10.