# CVE-2026-1555 - WordPress WebStack theme io_img_upload() (unauthenticated AJAX action
# img_upload) stores an uploaded file without validating its extension/MIME, allowing a
# .php upload and remote code execution. Detect the unauthenticated multipart POST to the
# img_upload action carrying a PHP file name.
alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"VEDAS CVE-2026-1555 WordPress WebStack Theme Unauthenticated Arbitrary File Upload (img_upload)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/wp-admin/admin-ajax.php"; fast_pattern; http.request_body; content:"img_upload"; nocase; content:"filename="; nocase; distance:0; pcre:"/filename=\x22?[^\x22\r\n]*\.(?:php|phtml|php5|php7|phar)\b/i"; classtype:web-application-attack; reference:cve,CVE-2026-1555; reference:url,https://www.exploit.observer/?keyword=CVE-2026-1555&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=webstack&match=exact; sid:1099001; rev:1;)