Ubuntu 24.04 is the clearest backport example in this incident. PHP’s fixed 8.3 release is 8.3.36. Ubuntu’s fixed php8.3 package is 8.3.6-0ubuntu0.24.04.13. Both statements are from primary sources. Installing 8.3.36 from a tarball on top of the Ubuntu modules is how you break the package manager. Installing the Ubuntu revision is how you take Ubuntu’s fix.
Check:
apt-cache policy php8.3-fpm
php -v
Expect php -v to keep a line that includes 8.3.6. Expect policy to show the ubuntu0.24.04.13 revision or a later Ubuntu revision that replaces it. Restart php8.3-fpm or Apache after the install.
Noble uses PHP-FPM in the default integration. Confirm the vhost’s socket is php8.3-fpm.sock. A site forced onto a PPA build of 8.2 is outside this package.
This revision is standard support, not ESM. You do not need Ubuntu Pro for 24.04 to see it, according to Ubuntu’s post.