Security Advisories (4)
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-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.

CVE-2026-8376 (2026-05-25)

Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer. A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.

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

ODBM_File - Tied access to odbm files

SYNOPSIS

use Fcntl;   # For O_RDWR, O_CREAT, etc.
use ODBM_File;

 # Now read and change the hash
 $h{newkey} = newvalue;
 print $h{oldkey}; 
 ...

 untie %h;

DESCRIPTION

ODBM_File establishes a connection between a Perl hash variable and a file in ODBM_File format;. You can manipulate the data in the file just as if it were in a Perl hash, but when your program exits, the data will remain in the file, to be used the next time your program runs.

Use ODBM_File with the Perl built-in tie function to establish the connection between the variable and the file. The arguments to tie should be:

  1. The hash variable you want to tie.

  2. The string "ODBM_File". (Ths tells Perl to use the ODBM_File package to perform the functions of the hash.)

  3. The name of the file you want to tie to the hash.

  4. Flags. Use one of:

    O_RDONLY

    Read-only access to the data in the file.

    O_WRONLY

    Write-only access to the data in the file.

    O_RDWR

    Both read and write access.

    If you want to create the file if it does not exist, add O_CREAT to any of these, as in the example. If you omit O_CREAT and the file does not already exist, the tie call will fail.

  5. The default permissions to use if a new file is created. The actual permissions will be modified by the user's umask, so you should probably use 0666 here. (See "umask" in perlfunc.)

DIAGNOSTICS

On failure, the tie call returns an undefined value and probably sets $! to contain the reason the file could not be tied.

odbm store returned -1, errno 22, key "..." at ...

This warning is emitted when you try to store a key or a value that is too long. It means that the change was not recorded in the database. See BUGS AND WARNINGS below.

SECURITY AND PORTABILITY

Do not accept ODBM files from untrusted sources.

On modern Linux systems these are typically GDBM files, which are not portable across platforms.

The GDBM documentation doesn't imply that files from untrusted sources can be safely used with libgdbm.

Systems that don't use GDBM compatibilty for old dbm support will be using a platform specific library, possibly inherited from BSD systems, where it may or may not be safe to use an untrusted file.

A maliciously crafted file might cause perl to crash or even expose a security vulnerability.

BUGS AND WARNINGS

There are a number of limits on the size of the data that you can store in the ODBM file. The most important is that the length of a key, plus the length of its associated value, may not exceed 1008 bytes.

See "tie" in perlfunc, perldbmfilter, Fcntl