CVE-2026-27944
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNginx 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceNginx UI versions prior to 2.3.3 have an unauthenticated backup disclosure vulnerability. The /api/backup endpoint is accessible without authentication and exposes encryption keys in the X-Backup-Security response header, allowing attackers to download system backups and decrypt them using the disclosed keys. Backups contain highly sensitive data including user credentials, session tokens, SSL private keys, and Nginx configurations.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 2.3.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if Nginx UI is installedCheck for Nginx UI running on your server by examining running processes, checking for the nginx-ui binary, or reviewing reverse proxy configurations that route to a Nginx UI instance.Affected if Nginx UI is present in your environment
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Check the installed Nginx UI versionQuery the Nginx UI instance version endpoint, check the binary version if running locally, or review your package manager installation history.Affected if The version is below 2.3.3 (any version prior to 2.3.3)
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Verify if the /api/backup endpoint is accessibleSend an unauthenticated HTTP GET request to http://<your-server>/api/backup and observe the response code.Affected if The endpoint returns a 200 OK response without requiring authentication, indicating the vulnerability is present
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Check for the X-Backup-Security header exposureInspect the HTTP response headers from any request to the /api/backup endpoint for the X-Backup-Security header containing encryption keys.Affected if The X-Backup-Security header is present and contains encryption key material, confirming sensitive key disclosure
You are affected if Nginx UI version is below 2.3.3 and the /api/backup endpoint responds without authentication or exposes the X-Backup-Security header.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.3.3
Upgrade Nginx UI to version 2.3.3 or later. If immediate patching is not possible, implement network-level access controls to restrict the /api/backup endpoint to authorized users only.
2.3.3
- Ensure you have a complete backup of your current Nginx UI installation and configuration
- Stop the Nginx UI service
- Pull or download version 2.3.3 of Nginx UI from the official repository
- Upgrade your Nginx UI installation to version 2.3.3
- Verify the upgrade was successful by checking the version number
- Restart the Nginx UI service
- Test that the /api/backup endpoint now requires authentication
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-27944 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-27944 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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