CVE-2025-62491
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-16

Last updated on: 2025-10-30

Assigner: Google Inc.

Description
A Use-After-Free (UAF) vulnerability exists in the QuickJS engine's standard library when iterating over the global list of unhandled rejected promises (ts->rejected_promise_list). * The function js_std_promise_rejection_check attempts to iterate over the rejected_promise_list to report unhandled rejections using a standard list loop. * The reason for a promise rejection is processed inside the loop, including calling js_std_dump_error1(ctx, rp->reason). * If the promise rejection reason is an Error object that defines a custom property getter (e.g., via Object.defineProperty), this getter is executed during the error dumping process. * The malicious custom getter can execute JavaScript code that calls catch() on the same rejected promise being processed. * Calling catch() internally triggers js_std_promise_rejection_tracker, which then removes and frees the current promise entry (JSRejectedPromiseEntry) from the rejected_promise_list. * Since the list iteration continues using the now-freed memory pointer (el), the subsequent loop access results in a Use-After-Free condition.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-10-16
Last Modified
2025-10-30
Generated
2026-05-07
AI Q&A
2025-10-16
EPSS Evaluated
2026-05-05
NVD
CVE-2025-62491
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
quickjs_project quickjs to 2025-09-13 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a Use-After-Free (UAF) issue in the QuickJS engine's standard library. It occurs when iterating over the global list of unhandled rejected promises. During iteration, if a promise rejection reason has a custom property getter that executes JavaScript code calling catch() on the same rejected promise, the promise entry is removed and freed from the list. However, the iteration continues using the freed memory pointer, causing a Use-After-Free condition.


How can this vulnerability impact me? :

The Use-After-Free vulnerability can lead to undefined behavior such as crashes, memory corruption, or potentially arbitrary code execution within applications using the QuickJS engine. This can compromise application stability and security, possibly allowing attackers to execute malicious code or cause denial of service.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart