CVE-2026-4176

Perl vulnerability

9.8 CRITICALEPSS 0.81%

Published29 Mar 2026

Description

Perl versions from 5.9.4 before 5.40.4-RC1, from 5.41.0 before 5.42.2-RC1, from 5.43.0 before 5.43.9 contain a vulnerable version of Compress::Raw::Zlib. Compress::Raw::Zlib is included in the Perl package as a dual-life core module, and is vulnerable to CVE-2026-3381 due to a vendored version of zlib which has several vulnerabilities, including CVE-2026-27171. The bundled Compress::Raw::Zlib was updated to version 2.221 in Perl blead commit c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Perl≥ 5.41.0 < 5.42.2 · ≥ 5.43.0 < 5.43.9 · ≥ 5.9.4 < 5.40.4

Remediation

Fixed in

Perl≥ 5.42.2

Patch & vendor advisories

https://github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94

References

https://github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94Patch
https://lists.security.metacpan.org/cve-announce/msg/37638919/Third Party Advisory
https://metacpan.org/release/PMQS/Compress-Raw-Zlib-2.221/source/ChangesRelease Notes
https://metacpan.org/release/SHAY/perl-5.40.4/changesRelease Notes
https://metacpan.org/release/SHAY/perl-5.42.2/changesRelease Notes
https://www.cve.org/CVERecord?id=CVE-2026-3381Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/03/30/2Mailing ListThird Party Advisory

Frequently asked

Is CVE-2026-4176 being actively exploited?

CVE-2026-4176 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.81%.

How severe is CVE-2026-4176?

CVE-2026-4176 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.81% probability of exploitation.

Which products are affected by CVE-2026-4176?

Affected products include Perl.

How do I fix CVE-2026-4176?

Upgrade affected software to a fixed version, for example Perl 5.42.2 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-4176 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.