PHP 8.5.5 release candidate fixes critical JIT and memory bugs before final launch
The team behind the scripting language has pushed out the PHP 8.5.5 release candidate for testing purposes today. This update targets stability issues that often trip up production environments after an upgrade. Developers should check if their stack supports the latest JIT compiler improvements before committing to a full install.
Why the PHP 8.5.5 release candidate matters for your server setup
Stability is usually the main reason anyone waits for a patch series like this instead of jumping on version numbers immediately. The Opcache module received several patches that address memory leaks and incorrect arithmetic results from the JIT compiler. A common issue involved preloaded constants propagating to file-cached scripts which caused logic errors in long running daemons. Security researchers have flagged use after free vulnerabilities in the JIT tracing code as particularly dangerous for public facing web applications.
Performance gains and memory safety updates you need to know about
Beyond the engine internals there are specific library fixes that affect how data is handled during runtime. The DOM parser now correctly preserves xml:space attributes which saves hours of debugging when parsing legacy XML feeds. Developers working with image processing will appreciate the fix for identifying avif images using getimagesize without triggering false negatives. Memory leaks in Sysvshm and FFI modules have also been resolved because nobody wants their server eating RAM for no reason. Operators have noted that signal handler installation issues on AIX systems caused silent failures during process management tasks until this update arrived.
Release php-8.5.5RC1
Tag for php-8.5.5RC1
