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HTML-Parser-3.72
⭐ Starred 6 / HTML::Filter
Security Advisories (1)
CVE-2026-8829 (2026-06-04)

HTML::Entities versions before 3.84 for Perl read freed heap memory in _decode_entities. The XS routine backing HTML::Entities::_decode_entities cached a pointer (repl) into the entity-value SV returned by hv_fetch on the entity2char hash. When the input SV was identical to a value SV in that hash, and that value contained its own key as an entity reference, a later call to grow_gap() reallocated the SV's PV buffer and freed the backing allocation that repl still pointed into. The subsequent copy loop read repl_len bytes from the freed allocation. The read may disclose adjacent heap contents into the destination SV.

NAME

HTML::Filter - Filter HTML text through the parser

NOTE

This module is deprecated. The HTML::Parser now provides the functionally of HTML::Filter much more efficiently with the default handler.

SYNOPSIS

require HTML::Filter;
$p = HTML::Filter->new->parse_file("index.html");

DESCRIPTION

HTML::Filter is an HTML parser that by default prints the original text of each HTML element (a slow version of cat(1) basically). The callback methods may be overridden to modify the filtering for some HTML elements and you can override output() method which is called to print the HTML text.

HTML::Filter is a subclass of HTML::Parser. This means that the document should be given to the parser by calling the $p->parse() or $p->parse_file() methods.

EXAMPLES

The first example is a filter that will remove all comments from an HTML file. This is achieved by simply overriding the comment method to do nothing.

package CommentStripper;
require HTML::Filter;
@ISA=qw(HTML::Filter);
sub comment { }  # ignore comments

The second example shows a filter that will remove any <TABLE>s found in the HTML file. We specialize the start() and end() methods to count table tags and then make output not happen when inside a table.

  package TableStripper;
  require HTML::Filter;
  @ISA=qw(HTML::Filter);
  sub start
  {
     my $self = shift;
     $self->{table_seen}++ if $_[0] eq "table";
     $self->SUPER::start(@_);
  }

  sub end
  {
     my $self = shift;
     $self->SUPER::end(@_);
     $self->{table_seen}-- if $_[0] eq "table";
  }

  sub output
  {
      my $self = shift;
      unless ($self->{table_seen}) {
	  $self->SUPER::output(@_);
      }
  }

If you want to collect the parsed text internally you might want to do something like this:

package FilterIntoString;
require HTML::Filter;
@ISA=qw(HTML::Filter);
sub output { push(@{$_[0]->{fhtml}}, $_[1]) }
sub filtered_html { join("", @{$_[0]->{fhtml}}) }

SEE ALSO

HTML::Parser

COPYRIGHT

Copyright 1997-1999 Gisle Aas.

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