CVE-2026-13221

Name
CVE-2026-13221
Description
Perl versions through 5.43.9 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.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
9b29abf9-4ab0-4765-b253-1875cd9b441e https://github.com/Perl/perl5/commit/03f74bbbd3a68350d926ee93d56ee4808c28c4c7.patch
9b29abf9-4ab0-4765-b253-1875cd9b441e https://github.com/Perl/perl5/issues/23388
af854a3a-2127-422b-91ae-364da2661108 http://www.openwall.com/lists/oss-security/2026/07/13/5

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:* perl >= None <= 5.43.9

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
perl edge-main 5.42.2-r0 None possibly vulnerable
perl edge-main 5.42.1-r0 None possibly vulnerable
perl edge-main 5.42.0_rc3-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.42.0_rc2-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.42.0-r1 None possibly vulnerable
perl edge-main 5.42.0-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.40.2-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.40.1-r1 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.40.1-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.40.0-r3 Celeste <cielesti@protonmail.com> possibly vulnerable
perl edge-main 5.38.1-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl edge-main 5.34.0-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl edge-main 5.30.3-r0 None possibly vulnerable
perl edge-main 5.26.3-r0 None possibly vulnerable
perl edge-main 5.26.2-r1 None possibly vulnerable
perl edge-main 5.26.2-r0 None possibly vulnerable
perl edge-main 5.26.1-r0 None possibly vulnerable
perl 3.24-main 5.42.2-r0 None possibly vulnerable
perl 3.23-main 5.42.2-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.23-main 5.42.1-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.23-main 5.42.0-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.22-main 5.40.4-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.22-main 5.40.3-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.22-main 5.40.2-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.22-main 5.40.1-r1 None possibly vulnerable
perl 3.22-main 5.38.1-r0 None possibly vulnerable
perl 3.22-main 5.34.0-r1 None possibly vulnerable
perl 3.22-main 5.30.3-r0 None possibly vulnerable
perl 3.22-main 5.26.3-r0 None possibly vulnerable
perl 3.22-main 5.26.2-r1 None possibly vulnerable
perl 3.22-main 5.26.2-r0 None possibly vulnerable
perl 3.22-main 5.26.1-r0 None possibly vulnerable
perl 3.21-main 5.40.4-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.21-main 5.40.3-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.21-main 5.40.1-r1 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.21-main 5.40.1-r0 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.21-main 5.40.0-r3 Celeste <cielesti@protonmail.com> possibly vulnerable
perl 3.21-main 5.38.1-r0 None possibly vulnerable
perl 3.21-main 5.34.0-r1 None possibly vulnerable
perl 3.21-main 5.30.3-r0 None possibly vulnerable
perl 3.21-main 5.26.3-r0 None possibly vulnerable
perl 3.21-main 5.26.2-r1 None possibly vulnerable
perl 3.21-main 5.26.2-r0 None possibly vulnerable
perl 3.21-main 5.26.1-r0 None possibly vulnerable
perl 3.20-main 5.38.5-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.20-main 5.38.3-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.20-main 5.38.3-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.20-main 5.38.2-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.20-main 5.38.1-r0 None possibly vulnerable
perl 3.20-main 5.34.0-r1 None possibly vulnerable
perl 3.20-main 5.30.3-r0 None possibly vulnerable
perl 3.20-main 5.26.3-r0 None possibly vulnerable
perl 3.20-main 5.26.2-r1 None possibly vulnerable
perl 3.20-main 5.26.2-r0 None possibly vulnerable
perl 3.20-main 5.26.1-r0 None possibly vulnerable
perl 3.19-main 5.38.5-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.19-main 5.38.3-r1 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.19-main 5.38.3-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.19-main 5.38.2-r0 Natanael Copa <ncopa@alpinelinux.org> possibly vulnerable
perl 3.19-main 5.38.1-r0 None possibly vulnerable
perl 3.19-main 5.34.0-r1 None possibly vulnerable
perl 3.19-main 5.30.3-r0 None possibly vulnerable
perl 3.19-main 5.26.3-r0 None possibly vulnerable
perl 3.19-main 5.26.2-r1 None possibly vulnerable
perl 3.19-main 5.26.2-r0 None possibly vulnerable
perl 3.19-main 5.26.1-r0 None possibly vulnerable