CVE-2026-13221

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Source
https://cve.org/CVERecord?id=CVE-2026-13221
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-13221.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-13221
Downstream
ALPINE (1)
AZL (1)
CGA (10)
DEBIAN (1)
ECHO (1)
MGASA (1)
MINI (4)
OESA (3)
openSUSE (1)
RHSA (5)
RLSA (4)
ROOT (5)
SUSE (4)
UBUNTU (1)
Related
ALSA (4)
openSUSE (1)
SUSE (4)
Published
2026-07-13T15:40:11Z
Modified
2026-09-15T16:56:44Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H CVSS Calculator
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
Details

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.

Database specific 
{
    "cna_assigner":  "CPANSec",
    "cwe_ids":  [
        "CWE-190"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13221.json"
}
References

Affected packages

Git / github.com/perl/perl5

Affected ranges

Type
GIT
Repo
https://github.com/perl/perl5
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
03f74bbbd3a68350d926ee93d56ee4808c28c4c7
Database specific
Show details 
{
    "cpe":  "cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*",
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "last_affected":  "5.43.9"
        }
    ],
    "source":  [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

Other
GitLive-blead
perl-5a2
perl-5a9
if-0.*
if-0.0603
if-0.0604
if-0.0605
perl-1.*
perl-1.0
perl-2.*
perl-2.0
perl-3.*
perl-3.000
perl-3.044
perl-4.*
perl-4.0.00
perl-4.0.36
perl-5.*
perl-5.000
perl-5.000o
perl-5.001
perl-5.001n
perl-5.002
perl-5.002_01
perl-5.003
perl-5.005
perl-5.6.0
perl-5.7.0
perl-5.7.1
perl-5.7.2
perl-5.7.3
perl-5.8.0
perl-5.9.0
perl-5.9.1
perl-5.9.2
perl-5.9.3
perl-5.9.4
perl-5.9.5
v5.*
v5.10.0
v5.11.0
v5.11.1
v5.11.3
v5.11.4
v5.11.5
v5.12.0
v5.12.0-RC0
v5.12.0-RC1
v5.12.0-RC2
v5.12.0-RC3
v5.12.0-RC4
v5.12.0-RC5
v5.13.0
v5.13.1
v5.13.10
v5.13.11
v5.13.2
v5.13.3
v5.13.4
v5.13.5
v5.13.6
v5.13.7
v5.13.8
v5.13.9
v5.14.0
v5.14.0-RC1
v5.14.0-RC2
v5.14.0-RC3
v5.15.0
v5.15.1
v5.15.2
v5.15.3
v5.15.4
v5.15.5
v5.15.9
v5.16.0
v5.16.0-RC1
v5.16.0-RC2
v5.17.0
v5.17.2
v5.17.4
v5.17.6
v5.17.7
v5.17.7.0
v5.17.8
v5.17.9
v5.18.0
v5.18.0-RC1
v5.18.0-RC2
v5.18.0-RC3
v5.18.0-RC4
v5.19.0
v5.19.1
v5.19.11
v5.19.2
v5.19.3
v5.19.5
v5.19.7
v5.20.0
v5.20.0-RC1
v5.21.0
v5.21.1
v5.21.10
v5.21.11
v5.21.4
v5.21.5
v5.21.6
v5.21.8
v5.21.9
v5.22.0
v5.22.0-RC1
v5.22.0-RC2
v5.23.0
v5.23.1
v5.23.2
v5.23.3
v5.23.4
v5.23.6
v5.23.7
v5.24.0
v5.24.0-RC1
v5.24.0-RC2
v5.24.0-RC3
v5.24.0-RC4
v5.24.0-RC5
v5.25.0
v5.25.11
v5.25.2
v5.25.3
v5.25.4
v5.25.5
v5.25.7
v5.25.9
v5.26.0
v5.26.0-RC2
v5.27.0
v5.27.10
v5.27.11
v5.27.3
v5.27.5
v5.27.6
v5.27.7
v5.27.8
v5.28.0
v5.28.0-RC1
v5.28.0-RC2
v5.28.0-RC3
v5.28.0-RC4
v5.29.0
v5.29.1
v5.29.10
v5.29.5
v5.29.6
v5.29.7
v5.29.8
v5.29.9
v5.30.0
v5.30.0-RC1
v5.30.0-RC2
v5.31.0
v5.31.1
v5.31.11
v5.31.2
v5.31.3
v5.31.4
v5.31.5
v5.31.7
v5.32.0
v5.32.0-RC1
v5.33.0
v5.33.1
v5.33.2
v5.33.3
v5.33.4
v5.33.7
v5.33.8
v5.33.9
v5.34.0
v5.34.0-RC1
v5.34.0-RC2
v5.35.0
v5.35.10
v5.35.11
v5.35.3
v5.35.5
v5.35.6
v5.35.8
v5.35.9
v5.36.0
v5.36.0-RC3
v5.37.0
v5.37.1
v5.37.10
v5.37.11
v5.37.2
v5.37.3
v5.37.4
v5.37.5
v5.37.6
v5.37.7
v5.37.9
v5.38.0
v5.38.0-RC1
v5.38.0-RC2
v5.39.0
v5.39.1
v5.39.3
v5.39.4
v5.39.5
v5.39.7
v5.39.8
v5.40.0
v5.40.0-RC1
v5.40.0-RC2
v5.41.0
v5.41.1
v5.41.10
v5.41.11
v5.41.12
v5.41.13
v5.41.2
v5.41.3
v5.41.4
v5.41.5
v5.41.7
v5.41.8
v5.41.9
v5.42.0
v5.42.0-RC1
v5.42.0-RC2
v5.42.0-RC3
v5.43.0
v5.43.1
v5.43.2
v5.43.6
v5.43.8
v5.43.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-13221.json"
vanir_signatures 
[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "134675665719538900810772585221767670192",
                "162168684666736337369435135427539826229",
                "144872332641364083640948895312468990898"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-13221-64dd3400",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/perl/perl5/commit/03f74bbbd3a68350d926ee93d56ee4808c28c4c7",
        "target":  {
            "file":  "regcomp_study.c"
        }
    },
    {
        "deprecated":  false,
        "digest":  {
            "function_hash":  "236057087489884812036731213027052221607",
            "length":  42988
        },
        "id":  "CVE-2026-13221-945874b1",
        "signature_type":  "Function",
        "signature_version":  "v1",
        "source":  "https://github.com/perl/perl5/commit/03f74bbbd3a68350d926ee93d56ee4808c28c4c7",
        "target":  {
            "file":  "regcomp_study.c",
            "function":  "Perl_study_chunk"
        }
    }
]
vanir_signatures_modified 
"2026-09-10T08:11:41Z"