How severe is CVE-2026-27944?

CVE-2026-27944 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-27944 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27944?

CVE-2026-27944 affects Nginxui Nginx Ui. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27944?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-27944 have an EU (EUVD) identifier?

Yes. CVE-2026-27944 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9847.

When was CVE-2026-27944 published?

CVE-2026-27944 was published on 2026-03-05 and last updated on 2026-06-17.

CVE-2026-27944

CVE-2026-27944 is a critical-severity vulnerability in Nginxui Nginx Ui with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 22% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-306.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 22% (97th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9847
Weakness: CWE-306
Affected product: Nginxui Nginx Ui
Published: 2026-03-05
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-27944?: 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.
How severe is CVE-2026-27944?: CVE-2026-27944 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-27944 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27944?: CVE-2026-27944 affects Nginxui Nginx Ui. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27944?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-27944 have an EU (EUVD) identifier?: Yes. CVE-2026-27944 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9847.
When was CVE-2026-27944 published?: CVE-2026-27944 was published on 2026-03-05 and last updated on 2026-06-17.

References

https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-g9w5-qffc-6762

Affected products (1)

cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*

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