GHSA-8r5x-fm3f-whwj: handlebars (CVE-2026-106446)

Package	Ecosystem	Affected	Fixed in
handlebars	npm	>=4.0.0, <4.7.10	4.7.10

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The npm package handlebars, versions 4.0.0 up to but not including 4.7.10, is vulnerable to JavaScript injection through pre-parsed AST objects passed to compile() or precompile(). An attacker who can supply an object (such as a parsed JSON request body) to these functions can inject arbitrary JavaScript that runs on the server during rendering with compile(), or in wherever the precompiled output is loaded with precompile(). Upgrade to handlebars 4.7.10, which is the listed fixed version; applications that only pass template strings are not affected.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.8	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0079, the 56th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 13:33 UTC First seen by agentprime
31 Oct 2026, 13:33 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.