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Fencer Intel
high 7.3

CVE-2026-8376 json

Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds

published 5mo ago modified yesterday also EUVD-2026-31772

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds.

Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer.

A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.

Patch / fix

  • cpan perl 5.40.5-RC1, 5.42.3-RC1, 5.43.11
  • perl Debian 12 5.36.0-7+deb12u4
  • perl Debian 13 5.40.1-6+deb13u1
  • perl Debian 14 5.40.1-8

debian advisories DEBIAN-CVE-2026-8376

  • perl Ubuntu 22.04 LTS 5.34.0-3ubuntu1.7
  • perl Ubuntu 24.04 LTS 5.38.2-3.2ubuntu0.3
  • perl Ubuntu 25.10 5.40.1-6ubuntu0.1
  • perl Ubuntu 26.04 LTS 5.40.1-7ubuntu0.1
  • perl Ubuntu Pro 14.04 LTS 5.18.2-2ubuntu1.7+esm7
  • perl Ubuntu Pro 18.04 LTS 5.26.1-6ubuntu0.7+esm2
  • perl Ubuntu Pro 20.04 LTS 5.30.0-9ubuntu0.5+esm2

ubuntu advisories UBUNTU-CVE-2026-8376

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • perl SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +13 more 5.26.1-150300.17.23.1
  • perl Linux Micro 6.1 5.38.2-slfo.1.1_3.1
  • perl Linux Micro 6.0 5.38.2-5.1
  • perl SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 5.42.0-160000.3.1
  • perl SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 5.18.2-12.35.1

suse advisories SUSE-SU-2026:3558-1SUSE-SU-2026:3540-1SUSE-SU-2026:23075-1SUSE-SU-2026:23008-1SUSE-SU-2026:22847-1SUSE-SU-2026:22929-1

  • perl openSUSE Leap 16.0 5.42.0-160000.3.1

opensuse advisories openSUSE-SU-2026:21411-1

  • perl Alpine 3.24 5.42.3-r0

alpine advisories ALPINE-CVE-2026-8376

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • perl Azure Linux 3.0 5.38.2-512

azure linux advisories AZL-87357

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-8376 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-8376 updated cvss 5.7

perl: Perl: Heap buffer overflow when compiling regular expressions on 32-bit builds

  • Red Hat Enterprise Linux 6 perl, perl-CGI, perl-core, perl-CPAN, perl-libs, perl-parent, +39 more Red Hat Enterprise Linux 7 perl, perl-core, perl-CPAN, perl-libs, perl-tests, perl-macros, +11 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perl, perl-IO, perl-libs, perl-open, perl-Test, perl-Errno, +19 more Red Hat Enterprise Linux 9 perl, perl-B, perl-if, perl-IO, perl-ph, perl-lib, +92 more
    not affected: inline mitigations already exist
  • Red Hat Enterprise Linux 10 perl Red Hat Hardened Images perl
    not affected: component not present
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.64% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected products

  • cpan perl
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)

Classification

Weakness
  • CWE-680 Integer Overflow to Buffer Overflow

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.