How severe is CVE-2026-4176?

CVE-2026-4176 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-4176 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4176?

CVE-2026-4176 affects Perl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-4176?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-4176 have an EU (EUVD) identifier?

Yes. CVE-2026-4176 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17044.

When was CVE-2026-4176 published?

CVE-2026-4176 was published on 2026-03-29 and last updated on 2026-06-17.

CVE-2026-4176

CVE-2026-4176 is a critical-severity vulnerability in Perl with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17044
Affected product: Perl
Published: 2026-03-29
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2026-4176?: CVE-2026-4176 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-4176 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4176?: CVE-2026-4176 affects Perl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-4176?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-4176 have an EU (EUVD) identifier?: Yes. CVE-2026-4176 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17044.
When was CVE-2026-4176 published?: CVE-2026-4176 was published on 2026-03-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:perl:perl:*:*:*:*:*:*:*:*

More vulnerabilities in Perl

CVE-2026-8376 — Critical (CVSS 9.8): Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed…
CVE-2022-48522 — Critical (CVSS 9.8): In Perl 5.34.0, function S_find_uninit_var in sv.c has a stack-based crash that can lead to remote code execution or…
CVE-2018-18314 — Critical (CVSS 9.8): Perl before 5.26.3 has a buffer overflow via a crafted regular expression that triggers invalid write operations.
CVE-2018-18311 — Critical (CVSS 9.8): Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers…
CVE-2018-18312 — Critical (CVSS 9.8): Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers…
CVE-2018-6913 — Critical (CVSS 9.8): Heap-based buffer overflow in the pack function in Perl before 5.26.2 allows context-dependent attackers to execute…

All CVEs affecting Perl →

Threat intelligence

Threat-intel indicators referencing this CVE:

182.93.50.90 (ipv4-addr)
103.165.139.145 (ipv4-addr)
121.40.151.192 (ipv4-addr)
40.83.182.122 (ipv4-addr)
121.84.147.45 (ipv4-addr)