[GHSA] GHSA-cv84-9p8j-fj68 (high) — icalendar has Algorithmic Complexity in Equality

GHSA-cv84-9p8j-fj68 Severity: high CVE: CVE-2026-55099

icalendar has Algorithmic Complexity in Equality

### Summary

`Component.__eq__` compares subcomponents in `O(2^n)` time relative to nesting depth. Because the parser accepts arbitrarily nested components, a sub-kilobyte `.ics` file is enough to make a single equality check run for minutes or hang indefinitely. Any application that compares