node-handlebars: Handlebars provides the power necessary to let users build semantic templates
CVE-2026-33937 is fixed in node-handlebars on 1 platform by DEBIAN-CVE-2026-33937 (version 3:4.7.9-1), released March 27, 2026. It is not reported as exploited. Patch Radar priority: Urgent.
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| node-handlebars · Debian 14 | 3:4.7.9-1 | DEBIAN-CVE-2026-33937 | Mar 27, 2026 |
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