Vulnerabilities

A crafted JavaScript input executed with the QuickJS release 2025-09-13, fixed in commit fcd33c1afa7b3028531f53cd1190a3877454f6b3 (2025-12-11),`qjs` interpreter using the `-m` option and a low memory limit can cause an out-of-memory condition followed by an assertion failure in JS_FreeRuntime (list_empty(&rt->gc_obj_list)) during runtime cleanup. Although the engine reports an OOM error, it subsequently aborts with SIGABRT because the GC object list is not fully released. This results in a denial of service.

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.

quickjs-ng through 0.9.0 has an incorrect size calculation in JS_ReadBigInt for a BigInt, leading to a heap-based buffer overflow. QuickJS before 2025-04-26 is also affected.

QuickJS before c4cdd61 has a build_for_in_iterator NULL pointer dereference because of an erroneous lexical scope of "this" with eval.

QuickJS commit 2788d71 was discovered to contain a stack-overflow via the component js_proxy_isArray at quickjs.c.

Buffer Overflow vulnerability in quickjs.c in QuickJS, allows remote attackers to cause denial of service. This issue is resolved in the 2020-07-05 release.