Prototype Pollution in handlebars

published 2019-06-05 7y ago modified 2026-09-10 2mo ago

cvss: 7.3; version 3.1, GitHub
cisa kev: Not listed; not in CISA's catalog
epss: —; no score, EPSS covers CVEs only
public exploits: 0; none known

Versions of `handlebars` prior to 4.0.14 are vulnerable to Prototype Pollution. Templates may alter an Objects' prototype, thus allowing an attacker to execute arbitrary code on the server.

## Recommendation

For handlebars 4.1.x upgrade to 4.1.2 or later. For handlebars 4.0.x upgrade to 4.0.14 or later.

Patch / fix

fixed in 1 links 4

npm handlebars 3.0.7, 4.0.14, 4.1.2

Is GHSA-q42p-pg8m-cqh6 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CVSS scores

assigned by	version	score	vector
GitHub	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem	package	affected	fixed in
npm	handlebars	>=4.1.0, <4.1.2 >=4.0.0, <4.0.14 <3.0.7	4.1.2 4.0.14 3.0.7

Classification

Weakness

CWE-471 Modification of Assumed-Immutable Data (MAID)

References

Sources

GitHub Advisory GHSA-q42p-pg8m-cqh6

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.