Access of Resource Using Incompatible Type ('Type Confusion') Affecting handlebars package, versions >=4.0.0 <4.7.10
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-HANDLEBARS-20574183
- published8 Oct 2026
- disclosed8 Oct 2026
- creditNick Mykhailyshyn, bhaswanthc, Lương Nguyễn Ngọc Đình, jmoritzc53, n0tra4e, hibrian827, Thai Son Dinh, Nikola Kojic, Ahmed Elmahgob, vk-can, PellaML, shenhuanageshei, kagebunsher, kustundag, ffasterss, sanmatte
Introduced: 8 Oct 2026
NewCVE-2026-106446 (opens in a new tab)How to fix?
Upgrade handlebars to version 4.7.10 or higher.
Overview
handlebars is an extension to the Mustache templating language.
Affected versions of this package are vulnerable to Access of Resource Using Incompatible Type ('Type Confusion') via the compiler's handling of pre-parsed AST objects passed to compile or precompile. When a caller supplies a hand-built or attacker-influenced AST directly to the compiler, AST node values such as path depths, path parts, literal values, content strings, hash pair keys, and block params are written into generated JavaScript code without sufficient validation, allowing an attacker to inject arbitrary code into the compiled template output. The fix moves all AST value validation into the compiler itself, so that values are checked at the point they are written into generated code rather than only at parse time.