Perl Regex Trie Compilation Integer Overflow Leading to Silent Match Corruption (CVE-2026-13221)
highOtherA flaw in Perl's regex engine (Perl_study_chunk) causes silent match corruption when an alternation pattern contains more than 65535 fixed-string branches, due to a 16-bit field overflow during trie compilation. This can produce false positive or false negative matches with no warning, undermining any security or filtering logic that relies on such patterns.
Updated Jul 15, 2026 · CVSS 9.1