CVE-2025-47778 is a medium-severity vulnerability classified under CWE-611, which pertains to Improper Restriction of XML External Entity (XXE) Reference. This vulnerability affects the Sulu content management system (CMS), an open-source PHP-based platform built on the Symfony framework. Specifically, the flaw exists in versions 2.5.21 through 2.5.24, 2.6.5 through 2.6.8, and 3.0.0-alpha1 through 3.0.0-alpha2. The vulnerability arises when an administrator user uploads an SVG file, which is processed via the XML DOM library. Because the XML parser does not properly restrict external entity references, an attacker can craft malicious SVG files that cause the system to load external data. This can lead to XXE attacks, which may allow an attacker to read local files, perform server-side request forgery (SSRF), or cause denial of service by exhausting resources. The vulnerability requires administrator privileges to upload the malicious SVG, and no user interaction beyond that is necessary. The issue has been patched in versions 2.5.25, 2.6.9, and 3.0.0-alpha3. As a temporary workaround, manual patching of the SvgFileInspector.php file in the MediaBundle can mitigate the risk by restricting or sanitizing the XML external entity processing. The CVSS 4.0 score is 6.1, reflecting a medium severity with network attack vector, low attack complexity, no privileges required beyond admin, no user interaction, and high impact on confidentiality, integrity, and availability. No known exploits are currently reported in the wild.

For European organizations using the Sulu CMS, this vulnerability poses a significant risk primarily to the confidentiality and integrity of their systems. Since the vulnerability requires an admin user to upload a malicious SVG, the threat is mostly internal or from compromised admin accounts. Successful exploitation could lead to unauthorized disclosure of sensitive files, internal network scanning via SSRF, or denial of service conditions impacting availability. This could disrupt business operations, compromise sensitive data, and potentially facilitate further lateral movement within the network. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, could face compliance violations and reputational damage if exploited. Given Sulu's use in digital content management, websites and intranet portals could be defaced or manipulated, affecting user trust and service continuity.

European organizations should immediately verify their Sulu CMS version and upgrade to the patched releases (2.5.25, 2.6.9, or 3.0.0-alpha3) as the primary mitigation step. If immediate upgrade is not feasible, manually patch the SvgFileInspector.php file within the MediaBundle to disable or properly restrict XML external entity processing. Additionally, implement strict access controls and monitoring on admin accounts to prevent unauthorized SVG uploads. Employ network segmentation and web application firewalls (WAFs) to detect and block suspicious outbound requests that may result from SSRF attempts. Regularly audit uploaded SVG files for malicious content and consider disabling SVG uploads if not essential. Finally, conduct security awareness training for administrators to recognize and prevent potential misuse of upload functionalities.