/ 
XML-LibXML-2.0209
/ XML::LibXML::XPathExpression
Security Advisories (1)
CVE-2026-8177 (2026-05-10)

XML::LibXML versions through 2.0210 for Perl read out-of-bounds heap memory when parsing XML node names containing truncated UTF-8 byte sequences. A node name ending in the middle of a multi byte UTF-8 sequence causes the parser to read past the end of the input string into adjacent heap memory. Any Perl process that passes attacker controlled strings to XML::LibXML's DOM node-name methods can reach this path on the default API. The likely consequence is a crash, causing denial of service.

NAME

XML::LibXML::XPathExpression - XML::LibXML::XPathExpression - interface to libxml2 pre-compiled XPath expressions

SYNOPSIS

use XML::LibXML;
my $compiled_xpath = XML::LibXML::XPathExpression->new('//foo[@bar="baz"][position()<4]');

# interface from XML::LibXML::Node

my $result = $node->find($compiled_xpath);
my @nodes = $node->findnodes($compiled_xpath);
my $value = $node->findvalue($compiled_xpath);

# interface from XML::LibXML::XPathContext

my $result = $xpc->find($compiled_xpath,$node);
my @nodes = $xpc->findnodes($compiled_xpath,$node);
my $value = $xpc->findvalue($compiled_xpath,$node);

$compiled = XML::LibXML::XPathExpression->new( xpath_string );

DESCRIPTION

This is a perl interface to libxml2's pre-compiled XPath expressions. Pre-compiling an XPath expression can give in some performance benefit if the same XPath query is evaluated many times. XML::LibXML::XPathExpression objects can be passed to all find... functions XML::LibXML that expect an XPath expression.

new()
$compiled = XML::LibXML::XPathExpression->new( xpath_string );

The constructor takes an XPath 1.0 expression as a string and returns an object representing the pre-compiled expressions (the actual data structure is internal to libxml2).

AUTHORS

Matt Sergeant, Christian Glahn, Petr Pajas

VERSION

2.0209

COPYRIGHT

2001-2007, AxKit.com Ltd.

2002-2006, Christian Glahn.

2006-2009, Petr Pajas.

LICENSE

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