16 years ago, there was a bug reported to zgrep where files with 1 newline caused it to behave incorrectly. It was patched without a CVE https://git.savannah.gnu.org/cgit/gzip.git/commit/zgrep.in?i...

This year, there was a bug reported to zgrep where files with 2 newlines caused it to behave incorrectly. It got a CVE and a front page hacker news post.

I give it very good odds this vulnerability has seen next to zero exploitation in the wild in either of the two cases above.