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perl-5.45.1
⭐ Starred 2013 / SelectSaver
Security Advisories (1)
CVE-2026-15534 (2026-08-09)

Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in S_regmatch. The regex engine's superlinear cache holds one bit per subject position for each participating WHILEM node, so the bit count is the subject length plus one times the number of nodes. Nothing checks that product for positive overflow of the signed 32-bit count: a 286331153 byte subject matched against a pattern with 15 participating nodes stores the count as 14, leaving a two byte cache. The cache is then indexed from the real match position and node number, so reads go past the end of the allocation, and on failure CACHEsayNO sets a bit past it. A caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.

NAME

SelectSaver - save and restore selected file handle

SYNOPSIS

use SelectSaver;

{
   my $saver = SelectSaver->new(FILEHANDLE);
   # FILEHANDLE is selected
}
# previous handle is selected

{
   my $saver = SelectSaver->new;
   # new handle may be selected, or not
}
# previous handle is selected

DESCRIPTION

A SelectSaver object contains a reference to the file handle that was selected when it was created. If its new method gets an extra parameter, then that parameter is selected; otherwise, the selected file handle remains unchanged.

When a SelectSaver is destroyed, it re-selects the file handle that was selected when it was created.