The Dumper method in Data::Dumper before 2.154, as used in Perl 5.20.1 and earlier, allows context-dependent attackers to cause a denial of service (stack consumption and crash) via an Array-Reference with many nested Array-References, which triggers a large number of recursive calls to the DD_dump function.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.