Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Handlebars provides the power necessary to let users build semantic templates. From 4.0.0 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.
    (CVE-2026-106445)

ID	Name	Product	Family	Type	Severity
474003	Echo: handlebars: security update to 4.7.10	Tenable Cloud Security	Echo Local Security Checks	Local	critical
474003	Echo: handlebars: security update to 4.7.10	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	critical
473853	SCA: security update for handlebars (GHSA-p8wg-vrv2-v86f)	Tenable Cloud Security	SCA Checks	Local	critical
473853	SCA: security update for handlebars (GHSA-p8wg-vrv2-v86f)	Tenable Self-Hosted Container Security	SCA Checks	Local	critical

Detections

Analytics

CVE-2026-106445

critical

Tenable Plugins

critical

critical

critical

critical