CVE-2026-27944 | Nginx UI: Unauthenticated Backup Download with Encryption Key Disclosure

Exp

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.

Published: 2026-03-05 Last update: 2026-03-10 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-27944 is rated High Exploit Risk (87.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 7.31%, 92th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.02% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-27944

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-27944

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 6.30% 7.31% +1.02%
2 2026-05-21 6.07% 6.30% +0.22%
3 2026-05-12 — 6.07% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27944

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-27944

GitHub Security Advisory for CVE-2026-27944

GHSA-g9w5-qffc-6762 · Severity: critical · Ecosystem: go — Nginx-UI Vulnerable to Unauthenticated Backup Download with Encryption Key Disclosure

Affected software / configurations for CVE-2026-27944

Vendor Product Version Raw CPE
nginxui nginx_ui < 2.3.3 cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*

References for CVE-2026-27944

cvelogic Threat Intelligence