CWE-73Weakness · CWE-73

CVE-2026-55477

HIGH · 7.2 CVSS v3.1 Published 2026-06-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable Zero-click

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 · unedited
3X-UI is a web control panel for managing Xray-core servers. Prior to 3.3.1, an authenticated administrator can abuse the database import functionality to achieve arbitrary file write on the host by modifying Xray configuration values stored in the database. This can be leveraged to obtain code execution and persistent access as the user running Xray (including root when Xray is running as root). This vulnerability is fixed in 3.3.1.

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 confidence

This is an authenticated arbitrary file write vulnerability in 3X-UI's database import functionality. An authenticated administrator can modify Xray configuration values stored in the database to achieve arbitrary file write on the host filesystem. This can be chained to achieve code execution and persistent access as the Xray service user (potentially root).

MitigationUpgrade to version 3.3.1 or later. If immediate patching is not possible, restrict administrative access to trusted personnel and monitor for suspicious database import activities.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify if 3X-UI is installed
    Look for the x-ui binary or service. Common locations: /usr/local/bin/x-ui, /usr/bin/x-ui, or check system services via 'systemctl list-units | grep x-ui' or 'ps aux | grep x-ui'
    Affected if 3X-UI process or binary is found on the system
  2. Determine installed 3X-UI version
    Access the 3X-UI web interface (typically port 2053 or 8080), navigate to the Settings or About page to view the version number. Alternatively, run 'x-ui version' from the command line if available
    Affected if Version is present and is below 3.3.1
  3. Verify administrative access is available
    Confirm the 3X-UI web interface is accessible and check if valid administrator credentials exist. Review /etc/x-ui/db or similar database file location if accessible
    Affected if Administrator authentication to 3X-UI is possible
  4. Confirm database import functionality exists
    Access the 3X-UI web panel, navigate to the backup/restore or database import section. This is typically found in Settings or Backup/Restore menu options
    Affected if Database import or restore feature is present and accessible to the authenticated administrator

The environment is affected if 3X-UI is installed with a version below 3.3.1 and the database import feature is accessible to an authenticated administrator.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to version 3.3.1 or later. If immediate patching is not possible, restrict administrative access to trusted personnel and monitor for suspicious database import activities.

Recommended fix High confidence

3.3.1

  1. Upgrade 3X-UI to version 3.3.1 or later
  2. After upgrading, verify the database import functionality no longer allows arbitrary file writes
  3. Test existing Xray configurations to ensure they work correctly after the upgrade
  4. Review administrator access controls and audit logs for any suspicious activity that may have occurred before the patch

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-55477 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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