EFence, a product developed by Thinking Software Technology, contains a critical Arbitrary File Upload vulnerability tracked as CVE-2026-80235. Unauthenticated remote attackers can exploit this flaw to upload web shell backdoors to the server. Once uploaded, these web shells can be executed, granting attackers the ability to run arbitrary code on the affected server. No authentication is required to exploit this vulnerability, making it particularly dangerous. The vulnerability poses a severe risk to organizations using EFence, as full server compromise is possible. The issue has been reported via Taiwan's TWCERT/CC advisory system. Exploitation could lead to data exfiltration, lateral movement, and full system takeover. The vulnerability is classified as high severity given its unauthenticated remote exploitability and potential for complete server compromise.
