CVE-2025-62490 Use-after-free in js_print_object in QuickJS
An attacker can trigger a use-after-free in QuickJS by exploiting side effects during array or map printing, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-62490?
CVE-2025-62490 is a high-severity use after free vulnerability in QuickJS, published on 16 Oct 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-416
Which versions are affected by CVE-2025-62490?
It affects 1 product.
Products include Quickjs Project Quickjs.
How do I fix CVE-2025-62490?
No fix has been published for CVE-2025-62490 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-62490 being exploited?
There is no known exploitation of CVE-2025-62490 in the wild and no public exploit code.
Other vulnerabilities in QuickJS
Sources
Also known as DEBIAN-CVE-2025-62490, GHSA-g55w-pj8g-frvg, UBUNTU-CVE-2025-62490.