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
Summary
| CVE | CVE-2026-4176 |
|---|---|
| State | PUBLISHED |
| Assigner | CPANSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-29 21:16:15 UTC |
| Updated | 2026-03-30 16:16:08 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.000190000 probability, percentile 0.050730000 (date 2026-04-01)
Problem Types: CWE-1395 CWE-1395 Dependency on Vulnerable Third-Party Component
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.cve.org/CVERecord | 9b29abf9-4ab0-4765-b253-1875cd9b441e | www.cve.org | |
| metacpan.org/release/SHAY/perl-5.40.4/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| metacpan.org/release/SHAY/perl-5.42.2/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| www.openwall.com/lists/oss-security/2026/03/30/2 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94 | 9b29abf9-4ab0-4765-b253-1875cd9b441e | github.com | |
| metacpan.org/release/PMQS/Compress-Raw-Zlib-2.221/source/Changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| lists.security.metacpan.org/cve-announce/msg/37638919 | 9b29abf9-4ab0-4765-b253-1875cd9b441e | lists.security.metacpan.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Bernhard Schmalhofer (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-02-27T00:00:00.000Z | Compress::Raw::Zlib 2.221 committed to Perl blead. |
| CNA | 2026-03-07T00:00:00.000Z | CVE-2026-3381 published for Compress::Raw::Zlib. |
| CNA | 2026-03-14T00:00:00.000Z | CVE-2026-4176 reserved. |
| CNA | 2026-03-29T00:00:00.000Z | Perl 5.40.4 and 5.42.2 released. |
Solutions
CNA: Update to Perl stable release 5.40.4 or 5.42.2 or later, which include Compress::Raw::Zlib 2.222.
Workarounds
CNA: Install Compress::Raw::Zlib 2.220 or later into your @INC include path, so it takes precedence over the vulnerable core module shipped with Perl. Some OS distributions patch their perl package to build Compress::Raw::Zlib against the system zlib rather than the vendored copy. Users of these distributions may not be affected if their system zlib has been updated to 1.3.2 or later, or includes backported patches for the relevant vulnerabilities.