BIT-php-min-2026-6104

In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, when an encoding name containing an embedded NUL byte is passed to mbconvertencoding() or related mbstring functions, the code incorrectly assumes that when strncasecmp() returns 0 it means the strings have the same length. This can lead to out-of-bounds read of global memory, potentially causing a crash or information disclosure or crash. Affected functions include mbconvertencoding(), mbdetectencoding(), mbconvertvariables(), and mbdetectorder(), as well as the mbstring.detectorder and mbstring.httpoutput INI settings.