Hi, I have run into issues with acknowledging alerts on pages where page name is longer than 18 characters. The ack page is just empty - it doesn't show any form. The acknowledge.cgi script throws "malloc(): memory corruption" error when its error output is redirected to some file. I have track it down to memory allocation in acknowledge.c on line 292: "re = (char *)malloc(8 + strlen(pagename));" I believe that allocating "(8 + strlen(pagename))" of memory for "re" is not enough if we put the pagename into it twice in the next line "sprintf(re, "%s$|^%s/.+", pagename, pagename);". I'm not quite sure why it works for names shorter than 19 chars though. Following change to acknowledge.c seems to fix the issue: --- acknowledge.c 2014-01-27 16:56:50.000000000 +0000 +++ acknowledge.c.new 2014-08-07 13:01:03.000000000 +0100 @@ -289,7 +289,7 @@ pcre *dummy; char *re; - re = (char *)malloc(8 + strlen(pagename)); + re = (char *)malloc(8 + strlen(pagename)*2); sprintf(re, "%s$|^%s/.+", pagename, pagename); dummy = compileregex(re); if (dummy) { This was tested on 64 bit Ubuntu 14.04 running xymon 4.3.17. Regards, Martin