From what I've seen in the bounty-related subreddits, AI is flooding bug bounty inboxes with low-value or meaningless reports, or straight-up hallucinations when people use smaller models (to turn a profit, you make lots of low-value bug reports and see who pays out).

This has a negative effect on humans doing their work with or without LLMs: curl shut down their bounty program, and GitHub just announced they're "restructuring" theirs. The author of this post also makes a case that HackerOne hasn't been honest about LLM training and use, either to hackers or to their own staff.