In PHP versions 8.1.* before 8.1.30, 8.2.* before 8.2.24, 8.3.* before 8.3.12, when using PHP-FPM SAPI and it is configured to catch workers output through catch_workers_output = yes, it may be possible to pollute the final log or remove up to 4 characters from the log messages by manipulating log message content. Additionally, if PHP-FPM is configured to use syslog output, it may be possible to further remove log data using the same vulnerability.
https://github.com/php/php-src/security/advisories/GHSA-865w-9rf3-2wh5