CVE-2026-27944

CVE-2026-27944 is a critical vulnerability in Nginx UI versions prior to 2.3.3, allowing unauthenticated attackers to access the /api/backup endpoint. This flaw discloses encryption keys in the X-Backup-Security header, enabling the download and decryption of full system backups containing sensitive data like user credentials and SSL private keys. With a CVSS score of 9.8 (CRITICAL), this vulnerability is easily exploitable over the network with low complexity, leading to complete compromise of confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community attention with over 12 mentions and media coverage. Organizations using affected Nginx UI versions should immediately upgrade to version 2.3.3 to mitigate this severe risk.