CVE-2026-4800

What it is

The fix for CVE-2021-23337 added validation for the variable option in _.template but did not apply the same validation to options.imports key names, and both paths flow into the same Function() constructor sink. When an application passes untrusted input as options.imports key names, an attacker can inject default-parameter expressions that execute arbitrary code at template compilation time. Additionally, _.template uses assignInWith to merge imports, which enumerates inherited properties via for..in, so if Object.prototype has been polluted by another vector the polluted keys are copied into the imports object and passed to Function(). The issue is fixed in 4.18.1 for lodash, lodash-es, lodash-amd, and lodash.template. As a workaround, do not pass untrusted input as key names in options.imports; use only developer-controlled, static key names.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

2.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-31 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-15 07:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.8% in the next 30 days (EPSS).
• Severity: 8.1 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-03-31 20:16 UTC

Last modified

2026-10-15 07:18 UTC

Exploit probability

2.8% · EPSS, next 30 days

Weakness

CWE-94 · Code injection

Record status

Modified

Affected

• Lodash < 4.18.0
• Lodash lodash-amd < 4.18.0
• Lodash lodash-es < 4.18.0
• Lodash lodash.template < 4.18.0

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-4800.md and follow it. Check whether this project is affected by CVE-2026-4800. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge