Is CVE-2026-106445 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-106445 being exploited in the wild.

How severe is CVE-2026-106445?

Critical severity, with a CVSS score of 4, published 6 October 2026.

Which products and versions are affected?

Handlebars 4.0.0 to 4.7.9; handlebars (npm) >= 4.0.0, <= 4.7.9, SEMVER:introduced=4.0.0,fixed=4.7.10.

Is there a fix for CVE-2026-106445?

Yes. handlebars (npm): upgrade to 4.7.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-106445 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-106445?

Check whether you run Handlebars or handlebars (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-106445: Handlebars prototype pollution RCE via constructor bypass

Q: Is there a fix for CVE-2026-106445?

Yes. handlebars (npm): upgrade to 4.7.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-106445 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-106445?

Check whether you run Handlebars or handlebars (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-106445 · Severity: critical · CVSS 4 · Published 2026-10-06

Handlebars is a templating engine used to generate dynamic web content. A flaw in how it validates template data access allows attackers to bypass security protections and execute arbitrary code on the server if they can control a template and certain settings are enabled. This could lead to complete server compromise and data theft.

Technologies: Handlebars, handlebars (npm). Vendors: Handlebars, npm.

Quick answers

Is CVE-2026-106445 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-106445 being exploited in the wild.
How severe is CVE-2026-106445?: Critical severity, with a CVSS score of 4, published 6 October 2026.
Which products and versions are affected?: Handlebars 4.0.0 to 4.7.9; handlebars (npm) >= 4.0.0, <= 4.7.9, SEMVER:introduced=4.0.0,fixed=4.7.10.
Is there a fix for CVE-2026-106445?: Yes. handlebars (npm): upgrade to 4.7.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-106445 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-106445?: Check whether you run Handlebars or handlebars (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

handlebars (npm): upgrade to 4.7.10 or later
```
npm install handlebars@4.7.10
```

Technical details

The lookupProperty function in Handlebars 4.0.0 through 4.7.9 returns Function.prototype.constructor before applying the prototype-access deny list, allowing an attacker to bypass prototype pollution protections via an own-property access. With allowProtoMethodsByDefault enabled and an accessible function in the template context, an attacker can traverse the prototype chain to obtain the Function constructor and execute arbitrary code with server privileges.

Affected products

Handlebars Handlebars 4.0.0 to 4.7.9

Identifiers

CVE-2026-106445
GHSA-p8wg-vrv2-v86f

Timeline

2026-10-06: disclosed

References

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