CVE-2026-2978 identifies a vulnerability in FastApiAdmin, an administrative interface framework for FastAPI applications, specifically affecting versions 2.0 through 2.2.0. The flaw resides in the upload_file_controller function within the Scheduled Task API module, located in /backend/app/api/v1/module_system/params/controller.py. This vulnerability permits an attacker to perform unrestricted file uploads remotely without requiring authentication or user interaction. The unrestricted upload capability means that an attacker can upload arbitrary files, potentially including malicious scripts or executables, to the server hosting the FastApiAdmin instance. Such an ability can lead to remote code execution, privilege escalation, data exfiltration, or denial of service. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no authentication required (AT:N), no user interaction (UI:N), and partial impacts on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). The exploit is publicly available, increasing the likelihood of exploitation, although no active exploitation has been reported yet. The vulnerability affects a critical administrative component, making it a significant risk for organizations relying on FastApiAdmin for backend management and scheduled task operations. The absence of official patches at the time of reporting necessitates immediate mitigation efforts.

The unrestricted file upload vulnerability can have severe consequences for organizations using FastApiAdmin. Attackers can upload malicious payloads such as web shells, ransomware, or backdoors, leading to full system compromise. This can result in unauthorized access to sensitive data, disruption of business operations, and potential lateral movement within the network. The vulnerability's remote exploitability without authentication makes it accessible to a wide range of attackers, including opportunistic threat actors and automated bots. Organizations in sectors with high-value data or critical infrastructure could face significant operational and reputational damage. Additionally, the public availability of the exploit code increases the risk of widespread attacks. The medium CVSS score reflects the moderate complexity but significant impact potential, especially if combined with other vulnerabilities or misconfigurations. Overall, the threat undermines the confidentiality, integrity, and availability of affected systems.

To mitigate CVE-2026-2978, organizations should immediately implement the following measures: 1) Apply any available patches or updates from FastApiAdmin developers as soon as they are released. 2) If patches are not yet available, restrict access to the upload_file_controller endpoint using network-level controls such as IP whitelisting, VPNs, or firewall rules to limit exposure. 3) Implement strict server-side validation of uploaded files, including checking file types, sizes, and contents to prevent malicious uploads. 4) Employ application-layer security controls such as web application firewalls (WAFs) configured to detect and block suspicious upload attempts. 5) Monitor logs and network traffic for unusual upload activity or access patterns targeting the Scheduled Task API. 6) Consider disabling or restricting the scheduled task upload functionality if it is not essential. 7) Conduct regular security assessments and penetration testing focused on file upload functionalities. 8) Educate development and operations teams about secure file handling practices to prevent similar vulnerabilities in the future.