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perl-5.42.2
⭐ Starred 2013 / vmsish
Security Advisories (3)
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-2026-57432 (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.

NAME

vmsish - Perl pragma to control VMS-specific language features

SYNOPSIS

use vmsish;

use vmsish 'status';	# or '$?'
use vmsish 'exit';
use vmsish 'time';

use vmsish 'hushed';
no vmsish 'hushed';
vmsish::hushed($hush);

use vmsish;
no vmsish 'time';

DESCRIPTION

If no import list is supplied, all possible VMS-specific features are assumed. Currently, there are four VMS-specific features available: 'status' (a.k.a '$?'), 'exit', 'time' and 'hushed'.

If you're not running VMS, this module does nothing.

vmsish status

This makes $? and system return the native VMS exit status instead of emulating the POSIX exit status.

vmsish exit

This makes exit 1 produce a successful exit (with status SS$_NORMAL), instead of emulating UNIX exit(), which considers exit 1 to indicate an error. As with the CRTL's exit() function, exit 0 is also mapped to an exit status of SS$_NORMAL, and any other argument to exit() is used directly as Perl's exit status.

vmsish time

This makes all times relative to the local time zone, instead of the default of Universal Time (a.k.a Greenwich Mean Time, or GMT).

vmsish hushed

This suppresses printing of VMS status messages to SYS$OUTPUT and SYS$ERROR if Perl terminates with an error status, and allows programs that are expecting "unix-style" Perl to avoid having to parse VMS error messages. It does not suppress any messages from Perl itself, just the messages generated by DCL after Perl exits. The DCL symbol $STATUS will still have the termination status, but with a high-order bit set:

EXAMPLE: $ perl -e"exit 44;" Non-hushed error exit %SYSTEM-F-ABORT, abort DCL message $ show sym $STATUS $STATUS == "%X0000002C"

$ perl -e"use vmsish qw(hushed); exit 44;"   Hushed error exit
$ show sym $STATUS
  $STATUS == "%X1000002C"

The 'hushed' flag has a global scope during compilation: the exit() or die() commands that are compiled after 'vmsish hushed' will be hushed when they are executed. Doing a "no vmsish 'hushed'" turns off the hushed flag.

The status of the hushed flag also affects output of VMS error messages from compilation errors. Again, you still get the Perl error message (and the code in $STATUS)

EXAMPLE: use vmsish 'hushed'; # turn on hushed flag use Carp; # Carp compiled hushed exit 44; # will be hushed croak('I die'); # will be hushed no vmsish 'hushed'; # turn off hushed flag exit 44; # will not be hushed croak('I die2'): # WILL be hushed, croak was compiled hushed

You can also control the 'hushed' flag at run-time, using the built-in routine vmsish::hushed(). Without argument, it returns the hushed status. Since vmsish::hushed is built-in, you do not need to "use vmsish" to call it.

EXAMPLE: if ($quiet_exit) { vmsish::hushed(1); } print "Sssshhhh...I'm hushed...\n" if vmsish::hushed(); exit 44;

Note that an exit() or die() that is compiled 'hushed' because of "use vmsish" is not un-hushed by calling vmsish::hushed(0) at runtime.

The messages from error exits from inside the Perl core are generally more serious, and are not suppressed.

See "Perl Modules" in perlmod.