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CVE-2026-106445

CVE-2026-106445 · Handlebars: JavaScript Injection via Own Property Check Bypass

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 9.2 · Critical · EPSS 0.6% · Public exploit · Fix available

Published
Updated

Stack: system · node

Affected products and versions

  • handlebars.js

    Versions
    • >= 3.0.0, < 4.7.10: Affected

    No fix published

  • node-handlebars Debian:12

    Versions
    • 3:4.7.10-1
    • 3:4.7.7+~4.1.0-1
    • 3:4.7.9-1
    • 3:4.7.9-2
    • 3:4.7.9-3
    • 3:4.7.9-4
    • 3:4.7.9-5
    • 3:4.7.9-6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Debian:13

    Versions
    • 3:4.7.10-1
    • 3:4.7.7+~4.1.0-1
    • 3:4.7.9-1
    • 3:4.7.9-2
    • 3:4.7.9-3
    • 3:4.7.9-4
    • 3:4.7.9-5
    • 3:4.7.9-6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Debian:14

    Versions
    • 3:4.7.7+~4.1.0-1
    • 3:4.7.9-1
    • 3:4.7.9-2
    • 3:4.7.9-3
    • 3:4.7.9-4
    • 3:4.7.9-5
    • 3:4.7.9-6
    Affected ranges
    • ECOSYSTEM: < 3:4.7.10-1

    Update to 3:4.7.10-1

  • handlebars npm

    Affected ranges
    • SEMVER: ≥ 3.0.0, < 4.7.10

    Update to 4.7.10

  • node-handlebars Ubuntu:18.04:LTS

    Versions
    • 3:4.0.10-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Ubuntu:20.04:LTS

    Versions
    • 3:4.1.0-1
    • 3:4.5.3-1
    • 3:4.7.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Ubuntu:22.04:LTS

    Versions
    • 3:4.7.6+~4.1.0-2
    • 3:4.7.7+~4.1.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Ubuntu:24.04:LTS

    Versions
    • 3:4.7.7+~4.1.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Ubuntu:26.10

    Versions
    • 3:4.7.7+~4.1.0-1
    • 3:4.7.9-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-handlebars Ubuntu:26.04:LTS

    Versions
    • 3:4.7.7+~4.1.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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