munin-cgi-graph for Munin 2.0 rc4 does not delete temporary files, which allows remote attackers to cause a denial of service (disk consumption) via many requests to an image with unique parameters.
The get_group_tree function in lib/Munin/Master/HTMLConfig.pm in Munin before 2.0.18 allows remote nodes to cause a denial of service (infinite loop and memory consumption in the munin-html process) via crafted multigraph data.