CVE-2026-48959

IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward

Published May 27, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward.

fastForward() compares length $offset (the digit count of the offset, 1 to 19) against the chunk size $c instead of $offset itself, so $c shrinks from 16 KiB to 1-19 bytes per iteration.

Extracting a named entry from an attacker supplied zip via IO::Uncompress::Unzip->new($zip, Name => $target) drives a per-byte read loop scaling with the entry's compressed size, up to the non-Zip64 4 GiB cap.

Remediation

Vendor Solution

Upgrade to IO-Compress 2.220 or later.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4812-1 libio-compress-perl security update
Debian DLA Debian DLA DLA-4821-1 perl security update
Ubuntu USN Ubuntu USN USN-8684-1 Perl vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Pmqs
Pmqs io::uncompress::unzip
Vendors & Products Pmqs
Pmqs io::uncompress::unzip
Type Values Removed Values Added
Description IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward. fastForward() compares length $offset (the digit count of the offset, 1 to 19) against the chunk size $c instead of $offset itself, so $c shrinks from 16 KiB to 1-19 bytes per iteration. Extracting a named entry from an attacker supplied zip via IO::Uncompress::Unzip->new($zip, Name => $target) drives a per-byte read loop scaling with the entry's compressed size, up to the non-Zip64 4 GiB cap.
Title IO::Uncompress::Unzip versions before 2.220 for Perl allow CPU exhaustion via per-byte read loop in fastForward
Weaknesses CWE-407
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Nov 10, 2026, 12:47 PM
Reserved
May 26, 2026, 6:09 PM
Status
Deferred
Published
May 27, 2026, 4:16 AM
Modified
Nov 10, 2026, 1:19 PM