CVE-2026-33937

Publication date 27 March 2026

Last updated 1 April 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

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.

Status

Package Ubuntu Release Status
node-handlebars 26.04 LTS resolute
Needs evaluation
25.10 questing Ignored end of life, was needs-triage
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation

Severity score breakdown

CVSS version: CVSS v3.0

Base score 9.8 · Critical

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Other references

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