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perl-5.45.1
⭐ Starred 2013 / File::Compare
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

File::Compare - Compare files or filehandles

SYNOPSIS

  	use File::Compare;

	if (compare("file1", "file2") == 0) {
	    print "They're equal\n";
	}

DESCRIPTION

The File::Compare::compare function compares the contents of two sources, each of which can be a file or a file handle. It is exported from File::Compare by default.

File::Compare::cmp is a synonym for File::Compare::compare. It is exported from File::Compare only by request.

File::Compare::compare_text does a line by line comparison of the two files. It stops as soon as a difference is detected. compare_text() accepts an optional third argument: This must be a CODE reference to a line comparison function, which returns 0 when both lines are considered equal. For example:

compare_text($file1, $file2)

is basically equivalent to

compare_text($file1, $file2, sub {$_[0] ne $_[1]} )

RETURN

File::Compare::compare and its sibling functions return 0 if the files are equal, 1 if the files are unequal, or -1 if an error was encountered.

AUTHOR

File::Compare was written by Nick Ing-Simmons. Its original documentation was written by Chip Salzenberg.