GHSA-4qw4-jpp4-8gvp: Unbounded resource exhaustion in cmark-gfm autolink extension may lead to denial of service

The vulnerability stems from cmark-gfm's autolink processing implementation. Key indicators:

1. The workaround suggests disabling autolink extension
2. The CWE-400 classification indicates algorithmic complexity issues
3. The patch involved updating to a cmark-gfm commit that specifically addresses autolink handling
4. Autolink parsing traditionally involves pattern scanning which is prone to quadratic complexity with nested loops
5. The reference to 'polynomial time complexity' strongly suggests functions with nested input-dependent loops
6. Historical context of similar vulnerabilities in markdown parsers often points to URI/email autolink handlers as hotspots for regex/scanning inefficiencies