Security Advisories (3)
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.
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
- https://github.com/Perl/perl5/commit/918bfff86ca8d6d4e4ec5b30994451e0bd74aba9.patch
- https://www.openwall.com/lists/oss-security/2025/05/22/2
- https://github.com/Perl/perl5/issues/23010
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1098226
- https://github.com/Perl/perl5/issues/10387
- https://perldoc.perl.org/5.14.0/perl5136delta#Directory-handles-not-copied-to-threads
- https://github.com/Perl/perl5/commit/11a11ecf4bea72b17d250cfb43c897be1341861e
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.
- https://www.cve.org/CVERecord?id=CVE-2026-3381
- https://lists.security.metacpan.org/cve-announce/msg/37638919/
- https://github.com/Perl/perl5/commit/c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94
- https://metacpan.org/release/PMQS/Compress-Raw-Zlib-2.221/source/Changes
- https://metacpan.org/release/SHAY/perl-5.40.4/changes
- https://metacpan.org/release/SHAY/perl-5.42.2/changes
NAME
gh7094 - benchmark speed for keys() on empty hashes
DESCRIPTION
If you have an empty hash, the speed of keys() depends on how many keys the hash previously held.
For global hashes, getting the count for previously big hashes was substantially slower than for lexical hashes.
This test checks that the speed difference for getting the number or list of keys from an empty hash is about the same (< 25%) for lexical and global hashes, both previously big and small.
REFERENCE
This test tests against GitHub ticket #7094
Module Install Instructions
To install less, copy and paste the appropriate command in to your terminal.
cpanm lessperl -MCPAN -e shell
install lessFor more information on module installation, please visit the detailed CPAN module installation guide.