CVE-2026-25870 is a server-side request forgery (SSRF) vulnerability identified in DoraCMS, an open-source content management system, specifically affecting versions 3.1 and prior. The vulnerability resides in the UEditor remote image fetch functionality, which allows users to submit URLs for the server to retrieve images. However, the server-side implementation lacks sufficient validation and destination restrictions, such as allowlists or blocking of internal/private IP ranges. Consequently, an attacker can craft malicious URLs that cause the server to initiate HTTP or HTTPS requests to arbitrary hosts, including internal network addresses that are typically inaccessible externally. This can facilitate internal network scanning, exposing sensitive infrastructure details, or lead to denial of service by exhausting server resources through large or slow responses. The vulnerability does not require any authentication or user interaction, increasing its exploitability. The CVSS 4.0 base score is 6.9 (medium severity), reflecting network attack vector, low attack complexity, no privileges or user interaction needed, and limited impact on integrity and availability. No public exploits are known at this time, but the lack of mitigations such as request timeouts or response size limits increases the risk of resource exhaustion attacks. The vulnerability highlights the importance of robust input validation and network request controls in web applications that fetch remote resources based on user input.

For European organizations, this SSRF vulnerability poses several risks. First, it can be leveraged to perform internal network reconnaissance, potentially exposing sensitive systems behind firewalls that are not otherwise accessible from the internet. This is particularly concerning for organizations with segmented networks or critical infrastructure protected by perimeter defenses. Second, attackers could exploit the vulnerability to cause denial of service by forcing the server to make numerous or slow requests, exhausting CPU, memory, or network bandwidth. This could disrupt availability of the CMS and dependent services. Third, if internal services have weak authentication or known vulnerabilities, SSRF could serve as a pivot point for further compromise. Given DoraCMS is used in various sectors including small to medium enterprises and possibly public sector websites, the impact could range from data exposure to operational disruption. The medium severity rating reflects that while the vulnerability is serious, it does not directly allow remote code execution or data exfiltration without additional conditions. However, the ease of exploitation without authentication and the potential to reach internal resources make it a significant concern for organizations relying on DoraCMS in Europe.

To mitigate CVE-2026-25870, organizations should first upgrade DoraCMS to a version where this vulnerability is patched once available. In the absence of an official patch, administrators should implement strict input validation on URLs accepted by the UEditor remote image fetch feature. This includes enforcing allowlists of trusted domains and explicitly blocking requests to private, loopback, link-local, and reserved IP address ranges (e.g., 10.0.0.0/8, 192.168.0.0/16, 127.0.0.0/8). Additionally, applying network-level controls such as firewall rules to restrict outbound HTTP/HTTPS requests from the CMS server can reduce risk. Implementing request timeouts and limiting response sizes can prevent resource exhaustion attacks. Monitoring and logging outbound requests initiated by the CMS can help detect suspicious activity. If feasible, disabling the remote image fetch feature entirely or restricting it to trusted users can further reduce exposure. Finally, organizations should conduct internal network scans to identify any sensitive services that could be targeted via SSRF and strengthen their security posture accordingly.