/ 
perl-5.42.0-RC1
⭐ Starred 2013 / PerlIO::scalar
Security Advisories (1)
CVE-2026-4176 (2026-03-29)

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.

NAME

PerlIO::scalar - in-memory IO, scalar IO

SYNOPSIS

my $scalar = '';
...
open my $fh, "<",  \$scalar or die;
open my $fh, ">",  \$scalar or die;
open my $fh, ">>", \$scalar or die;

or

my $scalar = '';
...
open my $fh, "<:scalar",  \$scalar or die;
open my $fh, ">:scalar",  \$scalar or die;
open my $fh, ">>:scalar", \$scalar or die;

DESCRIPTION

A filehandle is opened but the file operations are performed "in-memory" on a scalar variable. All the normal file operations can be performed on the handle. The scalar is considered a stream of bytes. Currently fileno($fh) returns -1.

Attempting to open a read-only scalar for writing will fail, and if warnings are enabled, produce a warning.

IMPLEMENTATION NOTE

PerlIO::scalar only exists as a stub. One does not need to explicitly use PerlIO::scalar.