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Fencer Vulns
critical 9.8

CVE-2019-19919 json

Prototype Pollution in handlebars

published 2019-12-20 6 y ago modified 2026-09-10 1 mo ago also GHSA-w457-6q6x-cgp9 , EUVD-2019-0803

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
7.1%
EPSS 7.1% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

Versions of handlebars prior to 4.3.0 are vulnerable to Prototype Pollution leading to Remote Code Execution. Templates may alter an Object's __proto__ and __defineGetter__ properties, which may allow an attacker to execute arbitrary code through crafted payloads.

Patch / fix

  • npm handlebars 3.0.8, 4.3.0
  • tenable tenable.sc 5.19.0
  • node-handlebars Debian 14, Debian 13, Debian 12 3:4.5.3-1

debian advisories DEBIAN-CVE-2019-19919

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-19919 updated cvss 4.2

nodejs-handlebars: prototype pollution leading to remote code execution via crafted payloads

  • Red Hat OpenShift Container Platform 3.11 kibana Red Hat OpenShift Container Platform 4 kibana Red Hat Quay 3 nodejs-handlebars
    affected: no fix available
  • Red Hat RHPAM 7.13.1 async
    fixed: vendor fix RHSA-2023:1334

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

7.07% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm handlebars
>=4.0.0, <4.3.0
<3.0.8
4.3.0
3.0.8
rubygems bootstrap-wysihtml5-rails
>=0.3.3.5, <=0.3.3.8
 no fix listed

Classification

Weakness
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

Sources

Fencer Vulns 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.