CVE-2026-13221 (GCVE-0-2026-13221)
Vulnerability from cvelistv5
Published
2026-07-13 15:40
Modified
2026-09-08 21:30
Severity ?
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CWE
  • CWE-190 - Integer Overflow or Wraparound
Summary
Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.10 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.
References
Impacted products
Vendor Product Version
Version: 0   < 5.40.5-RC1
Version: 5.41.0   < 5.42.3-RC1
Version: 5.43.0   < 5.43.10
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