Vulnerability in Perl
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (56.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.001
Affected products
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (related, vendor-advisory, Third Party Advisory, vdb-entry)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (vendor-advisory, Third Party Advisory)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Patch, patch)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (release-notes, Release Notes)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-4176?
- CVE-2026-4176 is a critical-severity vulnerability in Perl, classified under CWE-1395. CVSS score: 9.8/10. Published 2026-03-29.
- How severe is CVE-2026-4176?
- Critical severity. CVSS v3 base score is 9.8 out of 10.