CVE-2026-106512 is a high-severity vulnerability in the MISP sachertortephp component where the CakeResponse::download() method improperly sanitizes filenames used in the Content-Disposition HTTP header. This flaw allows an authenticated user to craft filenames that inject HTTP header content, leading to stored cross-site scripting (XSS) when other users view affected pages. The vulnerability arises from two injection vectors: control characters causing header omission and double-quote characters enabling header parameter injection. Exploitation can result in session hijacking, data exfiltration, and unauthorized actions within the application context.
In the MISP sachertortephp library, the Xml::build() static method in lib/Cake/Utility/Xml.php contains a logic error in the conditional that gates network-based XML fetching. The original condition was written as: $options['readFile'] && strpos($input, 'http://') === 0 || strpos($input, 'https://') === 0. Because PHP's && operator has higher precedence than ||, the expression is evaluated as ($options['readFile'] && strpos($input, 'http://') === 0) || strpos($input, 'https://') === 0. As a result, when a caller explicitly sets the readFile option to false to disable file and URL reading, an input string beginning with https:// still satisfies the condition and triggers a network fetch via HttpSocket (configured to follow up to 10 redirects). The http:// branch is correctly gated by the readFile flag, but the https:// branch is not. An attacker who can influence the $input parameter passed to Xml::build() can therefore force the application to issue an outbound HTTPS request to an attacker-controlled or internal URL, even though the caller intended to suppress all remote reads. The fetched response is parsed as XML and may be returned to the caller, enabling information disclosure from internal services or external targets. This constitutes a Server-Side Request Forgery (SSRF) weakness with an information-disclosure impact. The vulnerability requires that the code path in Xml::build() be reachable with attacker-controlled input and that the readFile option be set to false (or the caller expects it to be false).