s/findvalue/findnodes/. It's also very silly to do the search twice. 

if ( $xc->findnodes( 'advisories/cve', $vuln )) {        
    for ( $xc->findvalue( 'advisories/cve', $vuln )) {
        push ( @cve_records, $_ );
    }
}

[download]

should be 

for my $cve_node ($xc->findnodes('advisories/cve', $vuln)) {
    push @cve_records, $cve_node->textContent();
}

[download]

By the way, 

$fnd_vuln_id = $_->findvalue('./@id');

[download]

should be 

my $fnd_vuln_id = $_->findvalue('./@id');

[download]

and it can be simplified to 

my $fnd_vuln_id = $_->findvalue('@id');

[download]

and even to 

my $fnd_vuln_id = $_->getAttribute('id');

[download]

By the way, it would probably make more sense to load the nodes /audit/vulnerabilities/vuln into a hash (keyed by the id attribute) before the loop instead of repeatedly searching the tree inside the loop.

Update: Added notes.

In reply to Re: XPath not behaving as expected... by ikegami
in thread XPath not behaving as expected... by spstansbury

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.