Security Advisories (1)
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

NAME

IO - load various IO modules

SYNOPSIS

use IO qw(Handle File); # loads IO modules, here IO::Handle, IO::File
use IO;                 # DEPRECATED

DESCRIPTION

IO provides a simple mechanism to load several of the IO modules in one go. The IO modules belonging to the core are:

IO::Handle
IO::Seekable
IO::File
IO::Pipe
IO::Socket
IO::Dir
IO::Select
IO::Poll

Some other IO modules don't belong to the perl core but can be loaded as well if they have been installed from CPAN. You can discover which ones exist with this query: https://metacpan.org/search?q=IO%3A%3A.

For more information on any of these modules, please see its respective documentation.

DEPRECATED

use IO;                # loads all the modules listed below

The loaded modules are IO::Handle, IO::Seekable, IO::File, IO::Pipe, IO::Socket, IO::Dir. You should instead explicitly import the IO modules you want.