CVE-2026-4176 (Critical) detected in multiple libraries

[mend-bolt-for-github]

CVE-2026-4176 - Critical Severity Vulnerability

Vulnerable Libraries - srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6, srcvendor/mport/2.7.6

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

srcvendor/mport/2.7.6

Library home page: https://github.com/MidnightBSD/src.git

Vulnerable Source Files (6)

/sys/contrib/zlib/zutil.c
/sys/contrib/zlib/inftrees.c
/sys/contrib/zlib/inffast.c
/sys/contrib/zlib/inftrees.h
/sys/contrib/zlib/inflate.h
/sys/contrib/zlib/uncompr.c

Found in base branches: stable/4.0, master

Vulnerability Details

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.

Publish Date: 2026-03-29

URL: CVE-2026-4176

CVSS 3 Score Details (9.8)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: High
  • Integrity Impact: High
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-03-29

Fix Resolution: https://github.com/Perl/perl5.git - v5.43.9,https://github.com/Perl/perl5.git - v5.40.4,https://github.com/Perl/perl5.git - v5.42.2

---

Step up your Open Source Security Game with Mend here