CVE-2026-44966: Velocity.js is a JavaScript implementation of the Apache Velocity template engine

Q: How do I fix CVE-2026-44966?

velocity.js: upgrade to newer than 2.1.5. Exact commands for each OS are on this page.

Q: Is CVE-2026-44966 being exploited?

CVE-2026-44966 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-44966 affect?

CVE-2026-44966 affects velocity.js. Severity is high (CVSS 8.3). Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocit

Q: How urgent is CVE-2026-44966?

Priority 55/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

This week

HIGH 8.3REMOTEWATCHLISTUPGRADE

CVE-2026-44966 is a high-severity flaw (CVSS 8.3) affecting velocity.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocity templates. If an application renders a template controlled by an attacker, it is possible to modify Object.prototype, potentially leading to Denial of Service (DoS) or Remote Code Execution (RCE) depending on

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 54%)
CISA exploited list	No
Weakness	CWE-1321
Published	2026-05-26
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: shepherdwind

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-26 22:16 UTCPublished CVE record published
2026-07-24 12:10 UTCUpdated Record last modified

shepherdwind velocity.js UPGRADE

Affected: <= 2.1.5

Fixed in: newer than 2.1.5

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls velocity.js

2. UPGRADE to newer than 2.1.5

npm install velocity.js@">2.1.5"

Exact fixes by distribution

npm · velocityjs · NO FIX YET · vulnerable: <= 2.1.5 · source

Fedora 46 · fzssh · FIXED · 1.4.0-2.fc46 · FEDORA-2026-8004fcd067 · source

sudo dnf upgrade --advisory=FEDORA-2026-8004fcd067

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/shepherdwind/velocity.js/security/advisories/GHSA-j658-c2gf-x6pq

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-44966?

velocity.js: upgrade to newer than 2.1.5. Exact commands for each OS are on this page.

Is CVE-2026-44966 being exploited?

CVE-2026-44966 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-44966 affect?

CVE-2026-44966 affects velocity.js. Severity is high (CVSS 8.3). Velocity.js is a JavaScript implementation of the Apache Velocity template engine. In 2.1.5 and earlier, a prototype pollution vulnerability was discovered in velocityjs. This issue occurs during the processing of #set directives in Velocit

How urgent is CVE-2026-44966?

Priority 55/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

References

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