# CVE-2026-33941: node-handlebars: Handlebars provides the power necessary to let users build semantic templates

CVE-2026-33941 is fixed in node-handlebars on 1 platform by DEBIAN-CVE-2026-33941 (version 3:4.7.9-1), released March 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-33941
- Priority: High
- CVSS: 8.2 (high)
- EPSS: 0.0030
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 27, 2026

## Description

Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the Handlebars CLI precompiler (`bin/handlebars` / `lib/precompiler.js`) concatenates user-controlled strings — template file names and several CLI options — directly into the JavaScript it emits, without any escaping or sanitization. An attacker who can influence template filenames or CLI arguments can inject arbitrary JavaScript that executes when the generated bundle is loaded in Node.js or a browser. Version 4.7.9 fixes the issue. Some workarounds are available. First, validate all CLI inputs before invoking the precompiler. Reject filenames and option values  that contain characters with JavaScript string-escaping significance (`"`, `'`, `;`, etc.). Second, use a fixed, trusted namespace string passed via a configuration file rather than  command-line arguments in automated pipelines. Third, run the precompiler in a sandboxed environment (container with no write access to sensitive  paths) to limit the impact of successful exploitation. Fourth, audit template filenames in any repository or package that is consumed by an automated  build pipeline.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-handlebars Debian 14 | 3:4.7.9-1 | [DEBIAN-CVE-2026-33941](https://patchblox.com/security/data/fix/linux/debian-cve-2026-33941.md) | Mar 27, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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