Heads-up: 8.4.27 / 8.5.12 images ship a SimpleXML double-free regression (php-src#24488) #1706

For users landing here after zend_mm_heap corrupted crashes on the 8.4.27 / 8.5.12 images: this is an upstream regression from the 21 October release (php/php-src#24488). SimpleXML objects caught in a reference cycle make the GC double-free their properties table; json_decode(json_encode($xml), true) is a common trigger.

The fix is approved (php/php-src#24494) and will arrive with the next upstream release; 8.3.36 and 8.2.35 are not affected. I understand the images track upstream without extra patches, so this is mainly so people can find the cause. Feel free to close.