Google V8 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters, as demonstrated by attacks against Node.js.
http://www.ocert.org/advisories/ocert-2011-003.html
http://www.nruns.com/_downloads/advisory28122011.pdf
http://www.kb.cert.org/vuls/id/903934
http://archives.neohapsis.com/archives/bugtraq/2011-12/0181.html