Security Advisories (6)
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-2026-57432 (2026-07-13)

Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds. A template derived from untrusted input can read heap memory past the buffer and return it to the caller.

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

CVE-2026-13221 (2026-07-13)

Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.

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

MIME::QuotedPrint - Encoding and decoding of quoted-printable strings

SYNOPSIS

use MIME::QuotedPrint;

$encoded = encode_qp($decoded);
$decoded = decode_qp($encoded);

DESCRIPTION

This module provides functions to encode and decode strings into and from the quoted-printable encoding specified in RFC 2045 - MIME (Multipurpose Internet Mail Extensions). The quoted-printable encoding is intended to represent data that largely consists of bytes that correspond to printable characters in the ASCII character set. Each non-printable character (as defined by English Americans) is represented by a triplet consisting of the character "=" followed by two hexadecimal digits.

The following functions are provided:

encode_qp( $str)
encode_qp( $str, $eol)
encode_qp( $str, $eol, $binmode )

This function returns an encoded version of the string ($str) given as argument.

The second argument ($eol) is the line-ending sequence to use. It is optional and defaults to "\n". Every occurrence of "\n" is replaced with this string, and it is also used for additional "soft line breaks" to ensure that no line end up longer than 76 characters. Pass it as "\015\012" to produce data suitable for external consumption. The string "\r\n" produces the same result on many platforms, but not all.

The third argument ($binmode) will select binary mode if passed as a TRUE value. In binary mode "\n" will be encoded in the same way as any other non-printable character. This ensures that a decoder will end up with exactly the same string whatever line ending sequence it uses. In general it is preferable to use the base64 encoding for binary data; see MIME::Base64.

An $eol of "" (the empty string) is special. In this case, no "soft line breaks" are introduced and binary mode is effectively enabled so that any "\n" in the original data is encoded as well.

decode_qp( $str )

This function returns the plain text version of the string given as argument. The lines of the result are "\n" terminated, even if the $str argument contains "\r\n" terminated lines.

If you prefer not to import these routines into your namespace, you can call them as:

use MIME::QuotedPrint ();
$encoded = MIME::QuotedPrint::encode($decoded);
$decoded = MIME::QuotedPrint::decode($encoded);

Perl v5.8 and better allow extended Unicode characters in strings. Such strings cannot be encoded directly, as the quoted-printable encoding is only defined for single-byte characters. The solution is to use the Encode module to select the byte encoding you want. For example:

use MIME::QuotedPrint qw(encode_qp);
use Encode qw(encode);

$encoded = encode_qp(encode("UTF-8", "\x{FFFF}\n"));
print $encoded;

COPYRIGHT

Copyright 1995-1997,2002-2004 Gisle Aas.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

MIME::Base64