The admin url can be discovered without prior knowledge of it's location by exploiting the X-Original-Url header on some configurations.
The bug comes from the Zend library and is patche by unsetting the header in the bootstrap process.
Unset the X-Original-Url header in the web server configuration.
The activation of these headers is coming from the Zend_Controller module. It appears this has been known to some degree since 2016 - https://peterocallaghan.co.uk/2016/12/magento-poisoning-cache/ (dead link now..)
Anees Hyder ( @anees0xdev ) via HackerOne https://hackerone.com/anees0x_dev/hacktivity
{
"cwe_ids": [
"CWE-200"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-02T23:12:57Z",
"nvd_published_at": "2026-02-04T22:15:59Z",
"severity": "MODERATE"
}