Bug#1138051: libio-compress-perl: CVE-2026-48959

[Salvatore Bonaccorso]

Source: libio-compress-perl
Version: 2.219-2
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>

Hi,

The following vulnerability was published for libio-compress-perl.

CVE-2026-48959[0]:
| 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-48959
    https://www.cve.org/CVERecord?id=CVE-2026-48959
[1] https://lists.security.metacpan.org/cve-announce/msg/40434381/
[2] https://github.com/pmqs/IO-Compress/commit/68db44076f4c1a86a2ffe53a958eac6cabaf72e2

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore