lighttpd before 1.4.26, and 1.5.x, allocates a buffer for each read operation that occurs for a request, which allows remote attackers to cause a denial of service (memory consumption) by breaking a request into small pieces that are sent at a slow rate.

response.c in Lighttpd 1.4.10 and possibly previous versions, when run on Windows, allows remote attackers to read arbitrary source code via requests that contain trailing (1) "." (dot) and (2) space characters, which are ignored by Windows, as demonstrated by PHP files.

lighttpd before 1.4.14 allows attackers to cause a denial of service (crash) via a request to a file whose mtime is 0, which results in a NULL pointer dereference.

The configuration file for the FastCGI PHP support for lighttpd before 1.4.28 on Debian GNU/Linux creates a socket file with a predictable name in /tmp, which allows local users to hijack the PHP control socket and perform unauthorized actions such as forcing the use of a different version of PHP via a symlink attack or a race condition.