CVE-2025-62490: Quickjs Project Quickjs

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

In quickjs, in js_print_object, when printing an array, the function first fetches the array length and then loops over it. The issue is, printing a value is not side-effect free. An attacker-defined callback could run during js_print_value, during which the array could get resized and len1 become out of bounds. This results in a use-after-free.A second instance occurs in the same function during printing of a map or set objects. The code iterates over ms->records list, but once again, elements could be removed from the list during js_print_value call.

Affected products

• Quickjs Project Quickjs: before 2025-09-13 (fixed in 2025-09-13)

Published 2025-10-16. Last modified 2026-06-17.