Critical severity · published Mar 5, 2026
CVE-2026-27944
Nginx UI: Unauthenticated Backup Download with Encryption Key Disclosure
9.8
CVSS
22.9%
EPSS
No
On KEV
Description
Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.3, the /api/backup endpoint is accessible without authentication and discloses the encryption keys required to decrypt the backup in the X-Backup-Security response header. This allows an unauthenticated attacker to download a full system backup containing sensitive data (user credentials, session tokens, SSL private keys, Nginx configurations) and decrypt it immediately. This issue has been patched in version 2.3.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)22.9% · higher than 98% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NG
nginx-ui · 0xJacky
< 2.3.3 · source: vendor
NU
Nginx UI · Nginxui
before 2.3.3 · source: NVD
In the news
VulnerabilityCritical
Critical Nginx UI flaw CVE-2026-27944 exposes server backups
Nginx UI flaw CVE-2026-27944 lets attackers download and decrypt server backups without authentication, exposing sensitive data on public management interfaces. A critical vulnerability in Nginx UI, tracked as CVE-2026-27944 (CVSS score of 9.8), allows attackers to download and decrypt full server backups without authentication. The flaw poses a serious risk to organizations exposing the management […]
Mar 8, 2026·Security Affairs
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27944
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27944
Exploit
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-g9w5-qffc-6762
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