Crash after using up a lot of RAM

We are running traffic server in forward proxy mode, on an 8 core Xeon with 16GiB RAM, and 500GiB disk allocated in storage.config. The operating system is Debian wheezy amd64, TS version is the git snapshot of the last commit of 2012-12-08, which is available in Debian experimental.

The cache runs quite good since the last restart at 18th December, and it uses more and more memory over the time, which is the expected behavior. But I find in log that the process crashed today and restarted automatically, and the only thing I know is that the process had used over 8GiB RAM, but no accurate number. Log entry:

NOTE: Traffic Server received Sig 11: Segmentation fault
/usr/bin/traffic_server - STACK TRACE:
/lib/x86_64-linux-gnu/libpthread.so.0(+0xf030)[0x2b7f99340030]
/usr/bin/traffic_server(RangeTransform::transform_to_range()+0x80)[0x4e5c90]
/usr/bin/traffic_server(RangeTransform::handle_event(int, void*)+0x308)[0x4e7a98]
/usr/bin/traffic_server(EThread::process_event(Event*, int)+0x92)[0x66a062]
/usr/bin/traffic_server(EThread::execute()+0x5db)[0x66aa6b]
/usr/bin/traffic_server[0x669202]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x6b50)[0x2b7f99337b50]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x2b7f9b7e9a7d]