Zod Uncontrolled Resource Consumption via Unbounded Array, Set, and Map Validation

Zod schema-validation library contains an uncontrolled resource consumption vulnerability that allows attackers to exhaust memory by submitting a large array, set or map to an application that uses a container schema without an explicit size constraint. The handleArrayResult parse logic in $ZodArray (and the equivalent set and map paths) accumulates every validation issue for each failing element with no cap or early termination, causing the process to allocate one issue object per element and crash under out-of-memory conditions. This is reachable in the default configuration whenever a container schema such as z.array() is declared without a size bound. The upstream change in commit e06a510 (pull request 6652, first released in 4.6.6) only moves the .max(), .length() and .size() size checks to run before element parsing, so it rejects oversized input for schemas that declare an explicit upper bound; per the maintainer, unbounded containers are unchanged. No released version remediates the unbounded (default) case described here, and an opt-in setting to cap total accumulated errors was proposed but not merged.

Source published

1 Oct 2026 17:11:13 UTC

Source modified

28 Oct 2026 17:28:14 UTC

Observed here

28 Oct 2026 18:46:48 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.2 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H