We received a security report yesterday of a regression in the Warp 2.0 series[1] related to Slowloris protection. Please see the issue for details. The important information is:
* Versions prior to 2.0 are not affected.
* Updating to 2.0.3.3 solves the problem.
Yesod users: I've just released a new version of yesod-platform which updates the warp dependency.
If there are any questions, please let me know.