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.
CVE-2026-27944
CRITICALPre-NVD 9.89.8Elevated
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.8 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 22%CVSS: 9.8Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(low)
- EG Risk
- 75(Attend)EG Risk 75/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity98% × 45%Exploitation40% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 22%
- EPSS %ILE
- 97%
- KEV
- Not listed
Published
March 5, 2026
Last Modified
June 17, 2026
Advisory Details (1)
Auto-updated Jul 27, 2026🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available
Unauthenticated Backup Download with Encryption Key Disclosure · Advisory · 0xJacky/nginx-ui · GitHub
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-g9w5-qffc-6762Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-27 12:54 UTCEG score recompute
- 2026-07-27 12:50 UTCOSV refresh
Publicly available exploits
(1 reference)Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Nucleihttp/cves/2026/CVE-2026-27944.yamlFirst seen Jan 1, 2026
Nginx UI < 2.3.3 - Information Disclosure
Open source ↗
Frequently asked(5)
What is CVE-2026-27944?
CVE-2026-27944 is a critical vulnerability published on March 5, 2026. 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…
When was CVE-2026-27944 disclosed?
CVE-2026-27944 was first published in the National Vulnerability Database on March 5, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27944 actively exploited?
CVE-2026-27944 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22% probability of exploitation in the next 30 days, which ranks it in the top 2.6% of all scored CVEs.
What is the CVSS score of CVE-2026-27944?
CVE-2026-27944 has a CVSS v3 base score of 9.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-27944?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27944, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27944
Is Your Infrastructure Affected by CVE-2026-27944?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.