CVE-2023-54404 Zod can exhaust memory while validating oversized constrained collections

Not scored Published 1 Oct 2026 Updated 28 Oct 2026

Attackers can cause denial of service by submitting large arrays to Zod schemas lacking length constraints, exhausting memory resources.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2023-54404?

CVE-2023-54404 is a denial of service vulnerability in zod, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

This CVE ID has been rejected or withdrawn by its CVE Numbering Authority. The described memory use only grows in proportion to input already allocated by JSON.parse before Zod runs, is reachable only without an application request-size limit, and reflects expected validator behavior rather than a defect in Zod.

Which versions are affected by CVE-2023-54404?

2 open source packages ship an affected version, including zod.

Package	Affected	Fixed in
`zod` npm	All versions	`4.6.6`
`zod` npm	All versions	`4.6.6`

How do I fix CVE-2023-54404?

Upgrade zod to 4.6.6 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-54404 being exploited?

There is no known exploitation of CVE-2023-54404 in the wild and no public exploit code.

Sources

Also known as CLSA-2026-1793221263, CLSA-2026-1793221310, CLSA-2026-1793241442, CLSA-2026-1793241599, CLSA-2026-1793241749, GHSA-mrhx-c7xc-m3w5 and 3 more.