CVE-2026-27944

CRITICALPre-NVD 9.89.8
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
Elevated
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.

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 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 computed
Severity98% × 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-6762

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/0xJacky/Nginx-UI—2.3.3—

Weakness 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.

  1. 2026-07-27 12:54 UTCEG score recompute
  2. 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.yaml
    First seen Jan 1, 2026

    Nginx UI < 2.3.3 - Information Disclosure

    Open source ↗

Related CVEs(same CWE)

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

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