Vulnerability · NVD published 2026-10-06
CVE-2026-106445
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.
- Disclosed
- 4 days →First PoC
Signals
- Exploited in the wild
- Not on KEVNot in CISA's catalogue as of the last daily pull. Absence is not proof of safety.
- EPSS · 30-day forecast
- 0%Chance of exploitation in the next 30 days, 34th percentile of all CVEs. A forecast; KEV outranks it.
- CVSS · NVD
- not stated by sourcesNo score published by NVD.
- Internet exposure
- not stated by sourcesNo exposure census on this CVE's dispatches.
Exploits
1 known · links onlyGitHub PoCs · by trust, then stars1
- murrez/CVE-2026-106445 ↗Trust ok 100
CVE-2026-106445 — Handlebars 4.0.0–4.7.9 RCE via Function.prototype.constructor bypass (GHSA-p8wg-vrv2-v86f). PoCbit PoC + Docker lab (4.7.9), check/exploit HTTP client, GHSA template chain. Fixed 4.7.10. https://pocbit.org/pocs/cve-2026-106445
★ 3 · created 2026-10-10
Fake proof-of-concept repositories have been used to deliver malware to the researchers who run them. The trust verdict is our engine's heuristic over the repository (account age, what it ships, how its stars arrived); it is a reason to read the code first, not a finding about its author.
On the wire
1 dispatchWatch this one?
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