table internal to the pyexpat module's copy of the expat library to avoid a
  denial of service due to hash collisions.  Patch by David Malcolm with some
  modifications by the expat project.

release of 2.6 for 2012.

    http://hg.python.org/cpython/rev/48705250232c
    changeset:   75187:48705250232c
    branch:      2.7
    parent:      75184:9a1d902714ae
    user:        Antoine Pitrou <solipsis@pitrou.net>
    date:        Wed Feb 22 22:16:25 2012 +0100

    changeset:   75153:9b7c6dd19e25
    branch:      2.7
    parent:      75151:b1a02c17b327
    user:        Antoine Pitrou <solipsis@pitrou.net>
    date:        Tue Feb 21 22:02:04 2012 +0100
    files:       Lib/test/test_os.py

    changeset:   75165:780008020c40
    user:        Antoine Pitrou <solipsis@pitrou.net>
    date:        Wed Feb 22 03:33:56 2012 +0100
    summary:     Fix (presumably) test_hash under big-endian systems (PPC).

have gotten randomized.

  environment variable, to provide an opt-in way to protect against denial of
  service attacks due to hash collisions within the dict and set types.  Patch
  by David Malcolm, based on work by Victor Stinner.

upon malformed POST request.