Vulnerability Details CVE-2025-62491
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 7.0%
CVSS Severity
CVSS v3 Score 8.8
Products affected by CVE-2025-62491
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cpe:2.3:a:quickjs_project:quickjs:-
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cpe:2.3:a:quickjs_project:quickjs:2019-07-09
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cpe:2.3:a:quickjs_project:quickjs:2019-07-21
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cpe:2.3:a:quickjs_project:quickjs:2019-07-28
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cpe:2.3:a:quickjs_project:quickjs:2019-08-10
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cpe:2.3:a:quickjs_project:quickjs:2019-08-18
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cpe:2.3:a:quickjs_project:quickjs:2019-09-01
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cpe:2.3:a:quickjs_project:quickjs:2019-09-18
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cpe:2.3:a:quickjs_project:quickjs:2019-10-27
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cpe:2.3:a:quickjs_project:quickjs:2019-12-21
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cpe:2.3:a:quickjs_project:quickjs:2020-01-05
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cpe:2.3:a:quickjs_project:quickjs:2020-01-19
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cpe:2.3:a:quickjs_project:quickjs:2020-03-16
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cpe:2.3:a:quickjs_project:quickjs:2020-04-12
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cpe:2.3:a:quickjs_project:quickjs:2020-07-05
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cpe:2.3:a:quickjs_project:quickjs:2020-09-06
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cpe:2.3:a:quickjs_project:quickjs:2020-11-08
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cpe:2.3:a:quickjs_project:quickjs:2021-03-27
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cpe:2.3:a:quickjs_project:quickjs:2022-03-06
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cpe:2.3:a:quickjs_project:quickjs:2023-12-09
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cpe:2.3:a:quickjs_project:quickjs:2024-01-13