9.2
Critical
CVE-2026-106445 Handlebars provides the power necessary to let users build semantic templates
Description
Handlebars provides the power necessary to let users build semantic templates. From 3.0.0 until 4.7.10, Handlebars lookupProperty returns Function.prototype.constructor before applying the prototype-access deny list because constructor is an own property of Function.prototype. When an attacker can render a controlled template with allowProtoMethodsByDefault enabled and an accessible function in the template context, the template can traverse from that function through its prototype to Function.prototype and then obtain the Function constructor through the own-property bypass. This permits attacker-controlled JavaScript to execute with the server application's privileges. This issue is fixed in version 4.7.10.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| handlebars.js 3.0 | 3.0.0 → < 4.7.10 | 4.7.10 |
References
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
Timeline
- Published
- Last modified
Other CVEs of handlebars.js
The 9 CVEs of handlebars.js →
CVE-2026-106446
Handlebars provides the power necessary to let users build semantic templates
9.8
Critical
CVE-2026-106444
Handlebars provides the power necessary to let users build semantic templates
4.7
Medium
CVE-2026-33941
Handlebars provides the power necessary to let users build semantic templates
8.3
High
CVE-2026-33940
Handlebars provides the power necessary to let users build semantic templates
8.1
High