A AegiFlow
CRITICALCVSS 9.2EPSS 0.4%

CVE-2026-106445

CVE-2026-106445 updated by NVD

Published
2026-10-08
Modified
2026-10-14
EPSS percentile
34%
Sources
github-advisory, nvd

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.

Affected packages

EcosystemPackageAffected versionsFixed versions
npmhandlebars—4.7.10

Remediation: Upgrade to 4.7.10 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

CVE® is a registered trademark of The MITRE Corporation. CVE content reproduced under the CVE Terms of Use; copyright designation © MITRE.

EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.