CVE-2026-4176: SHAY perl

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

CVSS 9.8 CriticalCriticalEPSS 0.0074 · 54th percentile

Critical, because:

CVSS score 9.8: 9.0 or more.

How we decide what’s critical

Published by the CVE Program (CNA: CPANSec) at 29 Mar 2026, 20:50 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
SHAY	perl Package name: perl https://cpan.org/modules	affected 5.9.4 to before 5.40.4-RC1 custom affected 5.41.0 to before 5.42.2-RC1 custom affected 5.43.0 to before 5.43.9 custom Other versions: unaffected

Identifiers

CVE-2026-4176

CNA

CPANSec

Weakness (CWE)

CWE-1395

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.8	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	ADP (CISA-ADP)

CISA KEV Not listed.
EPSS 0.0074, the 54th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 29 Mar 2026. New records show when each source confirmed them.

Sources

References from the CNA

www.cve.org/CVERecord?id=CVE-2026-3381 vendor-advisoryrelatedvdb-entry
lists.security.metacpan.org/cve-announce/msg/37638919/ vendor-advisory
github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94 patch
metacpan.org/release/PMQS/Compress-Raw-Zlib-2.221/source/Changes release-notes
metacpan.org/release/SHAY/perl-5.40.4/changes release-notes
metacpan.org/release/SHAY/perl-5.42.2/changes release-notes

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.