CVE-2026-106445 (GCVE-0-2026-106445)
Vulnerability from cvelistv5 – Published: 2026-10-06 19:39 – Updated: 2026-10-12 14:33
VLAI
EPSS
VEX
Title
Handlebars: JavaScript Injection via Own Property Check Bypass
Summary
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-09 01:42 UTC
CWE
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/handlebars-lang/handlebars.js/… | x_refsource_CONFIRM |
| https://github.com/handlebars-lang/handlebars.js/… | x_refsource_MISC |
| https://github.com/handlebars-lang/handlebars.js/… | x_refsource_MISC |
| https://github.com/handlebars-lang/handlebars.js/… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| handlebars-lang | handlebars.js |
Affected:
>= 3.0.0, < 4.7.10
|
guessed |
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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