CVE-2026-27944
CriticalExploitedPublic exploitNginx-UI Vulnerable to Unauthenticated Backup Download with Encryption Key Disclosure
Published Mar 5, 2026 · Updated Aug 12, 2026 · Also known as GHSA-g9w5-qffc-6762, GO-2026-4614
Key Facts
Patch immediately- CVE-2026-27944 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Nginx Ui (Nginxui), github.com/0xJacky/Nginx-UI (go).
- It is exploited in the wild, listed in Industry KEV feed since Mar 19, 2026. Public exploit code is available.
- EPSS estimates a 1.0% probability of exploitation in the next 30 days.
- Fixed versions are available, including github.com/0xJacky/Nginx-UI 2.3.3, Nginx Ui 2.3.3.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
1.0%
Higher than 62.6% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-27944 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Mar 19, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Nginx UiNginxui | >= < 2.3.3 | 2.3.3 |
| github.com/0xJacky/Nginx-UIgo | See advisory | 2.3.3 |
Patched Releases
github.com/0xJacky/Nginx-UI
2.3.3
Nginx Ui
2.3.3
Timeline
Publicly disclosed
Mar 5, 2026
Added to Industry KEV feed
Mar 19, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-306 Missing Authentication for Critical Function
- CWE-311 Missing Encryption of Sensitive Data
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27944.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-27944
- articlehttps://csrc.nist.gov/publications/detail/sp/800-57-part-1/rev-5/final
- articlehttps://github.com/0xJacky/nginx-ui/security/advisories/GHSA-g9w5-qffc-6762
FAQ
Common Questions.
Nginx UI is a web user interface for the Nginx web server.
Affected: Nginx Ui (Nginxui) versions >= < 2.3.3; github.com/0xJacky/Nginx-UI (go). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Mar 19, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including github.com/0xJacky/Nginx-UI 2.3.3, Nginx Ui 2.3.3.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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