CVE-2026-33937: falha crítica em handlebars-lang handlebars.js
Handlebars.js has JavaScript Injection via AST Type Confusion
Publicada em · Atualizada em
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28Vexday Risk Score
Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.
ssvc Trackcvss 9.8epss 1.9%
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, `Handlebars.compile()` accepts a pre-parsed AST object in addition to a template string. The `value` field of a `NumberLiteral` AST node is emitted directly into the generated JavaScript without quoting or sanitization. An attacker who can supply a crafted AST to `compile()` can therefore inject and execute arbitrary JavaScript, leading to Remote Code Execution on the server. Version 4.7.9 fixes the issue. Some workarounds are available. Validate input type before calling `Handlebars.compile()`; ensure the argument is always a `string`, never a plain object or JSON-deserialized value. Use the Handlebars runtime-only build (`handlebars/runtime`) on the server if templates are pre-compiled at build time; `compile()` will be unavailable.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Produtos afetados
handlebars-lang · handlebars.jsCVEs relacionadas — handlebars-lang handlebars.js
No mesmo produto, das mais perigosas para as menos.
CVE-2026-106446CRITICALHandlebars: JavaScript Injection via AST Type Confusion in compile (Program.blockParams)EPSS 0.8%CVE-2026-33938HIGHHandlebars.js has JavaScript Injection via AST Type Confusion by tampering @partial-blockEPSS 0.7%CVE-2026-33940HIGHHandlebars.js has JavaScript Injection via AST Type Confusion when passing an object as dynamic partialEPSS 0.7%CVE-2026-33939HIGHHandlebars.js has Denial of Service via Malformed Decorator Syntax in Template CompilationEPSS 0.6%CVE-2026-106445CRITICALHandlebars: JavaScript Injection via Own Property Check BypassEPSS 0.6%CVE-2026-33941HIGHHandlebars.js has JavaScript Injection in CLI Precompiler via Unescaped Names and OptionsEPSS 0.3%
Referências
https://access.redhat.com/errata/RHSA-2026:10175https://access.redhat.com/errata/RHSA-2026:34342https://access.redhat.com/security/cve/CVE-2026-33937https://bugzilla.redhat.com/show_bug.cgi?id=2452523https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-2w6w-674q-4c4qhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33937.json