What is CVE-2026-33941?

CVE-2026-33941 is a high-severity vulnerability in Handlebars-lang Handlebars.js, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2026-03-27.

How severe is CVE-2026-33941?

High severity. CVSS v3 base score is 8.3 out of 10.

RCE in Handlebars-lang Handlebars.js

CVE-2026-33941

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 n…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (0.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/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-xjpj-3mr7-gcpf (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-2026-33941?: CVE-2026-33941 is a high-severity vulnerability in Handlebars-lang Handlebars.js, classified under Cross-site Scripting. CVSS score: 8.3/10. Published 2026-03-27.
How severe is CVE-2026-33941?: High severity. CVSS v3 base score is 8.3 out of 10.