RCE in Handlebars-lang Handlebars.js
CVE-2026-33938
Handlebars provides the power necessary to let users build semantic templates. In versions 4.0.0 through 4.7.8, the `@partial-block` special variable is stored in the template data context and is reachable and mutable from within a templat…
Vulnerability class: RCE (Remote Code Execution)
EPSS: 0.000 (15.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Handlebars-lang Handlebars.js — versions >= 4.0.0, < 4.7.9
Weakness classification (CWE)
References
- https://github.com/handlebars-lang/handlebars.js/security/advisories/GHSA-3mfm-83xf-c92r (x_refsource_CONFIRM)
- https://github.com/handlebars-lang/handlebars.js/commit/68d8df5a88e0a26fe9e6084c5c6aaebe67b07da2 (x_refsource_MISC)
- https://github.com/handlebars-lang/handlebars.js/releases/tag/v4.7.9 (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-33938?
- CVE-2026-33938 is a high-severity vulnerability in Handlebars-lang Handlebars.js, classified under Code Injection. CVSS score: 8.1/10. Published 2026-03-27.
- How severe is CVE-2026-33938?
- High severity. CVSS v3 base score is 8.1 out of 10.