PYSEC-2026-4304 Twisted: IMAP wildcardToRegexp() ReDoS

Summary wildcardToRegexp in twisted/mail/imap4.py converts IMAP LIST/LSUB wildcard patterns to Python regular expressions. It substitutes the two IMAP wildcards → ?:.? and % → ?:?:^\/? but passes every other character through unchanged to re.compile. This means that an authenticated IMAP client...