Pod::Text versions before 6.1.1 for Perl allow CPU and memory exhaustion formatting a POD document whose =over nesting drives the margin to the output width.
Each =over adds its indent to the margin, which wrap() subtracts from the output width to get the space available for text. When that space reaches zero, the line-splitting substitution matches the empty string, and the loop consumes no input while appending the margin padding on every pass.
Formatting an attacker-supplied POD document never returns, and the output grows until memory is exhausted.
Weakness
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.