dbcve.org
Unifi AccessApplication · Ui

CVE-2026-55117

HIGH · 8.6 CVSS v3.1 Published 2026-07-02
Fix available
A fix is available. Upgrade to 4.2.29 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 8 weeks old

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
A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi Access Application to access files on the host device.

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 · moderate confidence

A Path Traversal vulnerability in UniFi Access Application allows a network-adjacent attacker to escape the intended directory and read arbitrary files on the host system using '../' sequences in file path requests.

MitigationApply vendor patches when available; as an interim measure, implement strict input validation on file path parameters and restrict file system permissions to minimize exposure.

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
Unifi AccessApplication
Affected:< 4.2.29

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
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

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 UniFi Access Application is installed
    Check running processes or installed packages for 'unifi-access', 'ua', or 'UniFi Access' services. On Linux, check systemctl status or ps aux for related processes. On Windows, check Services panel or installed programs.
    Affected if The application is present and running on the system
  2. Determine the installed version of UniFi Access Application
    Check the application version through its web interface, command-line interface, or version file. Common locations: /opt/unifi-access/version, the web UI dashboard, or ua --version command if CLI is available. Compare against the affected range: < 4.2.29
    Affected if The installed version is any version lower than 4.2.29
  3. Verify the application is network accessible
    Check if the UniFi Access Application web interface or API ports are exposed to network traffic. Use netstat, ss, or nmap to identify listening ports (typically 443, 8443, or custom ports for UniFi). Check firewall rules and network configuration.
    Affected if The application is reachable from the network without proper segmentation
  4. Confirm the file path parameter feature is enabled
    Identify if the application exposes any file upload, download, or file serving endpoints that accept path parameters. Review the application's API documentation or test for endpoints that accept file path inputs.
    Affected if The application exposes any endpoint that accepts file path parameters without proper validation

A user is affected if UniFi Access Application version is below 4.2.29 and the file path parameter feature is accessible from the network.

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
Upgrade available Upgrade to 4.2.29 or later
Fixed in 4.2.29
Interim mitigation

Apply vendor patches when available; as an interim measure, implement strict input validation on file path parameters and restrict file system permissions to minimize exposure.

Recommended fix Moderate confidence

UniFi Access Application 4.2.29 or later

  1. Access the UniFi Access Application controller or management interface
  2. Navigate to the system settings or maintenance section
  3. Download UniFi Access Application version 4.2.29 or later from the official Ubiquiti downloads page (ui.com/downloads)
  4. Backup the current UniFi Access configuration before upgrading
  5. Perform the upgrade following standard Ubiquiti UniFi upgrade procedures
  6. Verify the upgrade was successful by checking the version number in the application UI
  7. Confirm the path traversal vulnerability is resolved by verifying file access restrictions
Caveat Review Ubiquiti release notes for 4.2.29 for any configuration or feature changes before upgrading

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

Fix this in Unifi Access Scoped from the published advisory
  • Consultation3.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
24.0 hours of engineering $4,200
Get the upgrade done

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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-2026-55117 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data