libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
Exploitability
AV:LAC:LAT:PPR:LUI:NVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:NSA:NCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N