CVE-2026-4176 | 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

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.

Published: 2026-03-29 Last update: 2026-06-17 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-4176 is rated Moderate Risk (56.4/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.68%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-4176

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.01% 0.68% +0.67%
2 2026-03-30 — 0.01% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-4176

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-4176

OS Trackers for CVE-2026-4176

vendor priority summary link
alpine — CVE-2026-4176: 1 source package rows (perl); 1 state rows across 1 repos (edge-main); fixed 1, open 0. https://security.alpinelinux.org/vuln/CVE-2026-4176
debian not yet assigned CVE-2026-4176 not yet assigned priority: Debian including 1 source packages (perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-4176
redhat medium — https://access.redhat.com/security/cve/CVE-2026-4176
ubuntu medium CVE-2026-4176 medium priority: Ubuntu including 1 source packages (perl), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 4, not-affected 3, released 1. https://ubuntu.com/security/CVE-2026-4176

Affected software / configurations for CVE-2026-4176

Vendor Product Version Raw CPE
perl perl >= 5.9.4, < 5.40.4 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*
perl perl >= 5.41.0, < 5.42.2 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*
perl perl >= 5.43.0, < 5.43.9 cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*

References for CVE-2026-4176

cvelogic Threat Intelligence