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perl-5.39.8
⭐ Starred 2013 / PerlIO::scalar
Security Advisories (3)
CVE-2024-56406 (2025-04-13)

A heap buffer overflow vulnerability was discovered in Perl. Release branches 5.34, 5.36, 5.38 and 5.40 are affected, including development versions from 5.33.1 through 5.41.10. When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.    $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'    Segmentation fault (core dumped) It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.

CVE-2025-40909 (2025-05-30)

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

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.