Let's see # uname -a OpenBSD cxib.laptop 4.3 CXKERNEL#0 i386 # export ZEND_MM_SEG_SIZE=8 # php -r 'phpinfo();' Segmentation fault (core dumped) # export ZEND_MM_SEG_SIZE=8 # gdb -q php (gdb) r Starting program: /usr/local/bin/php Program received signal SIGSEGV, Segmentation fault. 0x00000000 in ?? () (gdb) bt #0 0x00000000 in ?? () #1 0x1c1d3198 in zend_error (type=1, ... 0x1c1d3192 <zend_error+122>: call *0x3c0dc934 0x1c1d3198 <zend_error+128>: add $0x20,%esp (gdb) x/10x 0x3c0dc934 0x3c0dc934 <zend_error_cb>: 0x00000000 0x00000000 0x00000000 0x00000000 0x3c0dc944 <zval_used_for_init+8>: 0x00000000 0x00000000 0x00000000 0x00000000 0x3c0dc954 <zval_used_for_init+24>: 0x00000000 0x00000000 It dosent have a security impact. Credit: Maksymilian Arciemowicz