That rumor floated around Twitter but the company quickly disavowed it. The problem was that they added an extra parameter to a common function but never tested it with a non-wildcard value, revealing a gap in their code coverage review:
From the report, it seems the problem is that they added a feature that could use 21 arguments, but there was only enough space for 20. Until now, no configuration used all 21 (the last one was a wildcard regex, which apparently didn't count), but when they finally did, it caused a buffer overflow and crashed.
From my limited understanding, the file was corrupted in some way. Lots of NULL bytes, something like that.