CVE-2026-4176Perl 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
- 9.8CriticalCVSS base score
- 0.74%Exploitation in 30 daysEPSS · top 45% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By CPANSec
- 15 days later
· 15 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.74% · top 45% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
What to do
Solution: Update to Perl stable release 5.40.4 or 5.42.2 or later, which include Compress::Raw::Zlib 2.222.
Workaround: 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.
References
References7
- https://www.cve.org/CVERecord?id=CVE-2026-3381 (opens in a new tab)vendor-advisoryrelatedvdb-entry
- https://lists.security.metacpan.org/cve-announce/msg/37638919/ (opens in a new tab)vendor-advisory
- https://github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94 (opens in a new tab)patch
- https://metacpan.org/release/PMQS/Compress-Raw-Zlib-2.221/source/Changes (opens in a new tab)release-notes
- https://metacpan.org/release/SHAY/perl-5.40.4/changes (opens in a new tab)release-notes
- https://metacpan.org/release/SHAY/perl-5.42.2/changes (opens in a new tab)release-notes
- http://www.openwall.com/lists/oss-security/2026/03/30/2 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-17044 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-4176)Record last updated .