CVE-2026-54403 — Path Traversal in Ubiquiti Inc Cloud Gateways
A malicious actor with access to the network could exploit a Path Traversal vulnerability found in certain devices running UniFi OS to bypass authentication of such UniFi OS devices or instances.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Ubiquiti Inc Cloud Gateways, Ubiquiti Inc Cloud Keys, Ubiquiti Inc Dream Machines…).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Ubiquiti Inc | Cloud Gateways | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Cloud Keys | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Dream Machines | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Dream Routers | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Dream Wall | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Enterprise Firewall Core | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Enterprise Fortress Gateway | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Enterprise Video Recorders | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Express 7 | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Network Attached Storage | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | Network Video Recorders | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ubiquiti Inc | UniFi OS Server | < 5.1.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Ui | Enterprise Firewall Core Firmware | ≤ 5.1.18 | Vulnerable | NIST National Vulnerability Database |
| Ui | Enterprise Fortress Gateway Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Enterprise Network Video Recorder Core Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Enterprise Network Video Recorder Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unas 2 Firmware | ≤ 5.1.16 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unas 4 Firmware | ≤ 5.1.16 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unas Pro 4 Firmware | ≤ 5.1.16 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unas Pro 8 Firmware | ≤ 5.1.16 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unas Pro Firmware | ≤ 5.1.16 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloud Gateway Fiber Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloud Gateway Industrial Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloud Gateway Max Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloud Gateway Ultra Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloud Key Plus Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloudkey Enterprise Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Cloudkey Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Machine Beast Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Machine Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Machine Pro Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Machine Pro Max Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Machine Special Edition Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Router 5g Max Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Router 7 Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Router Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Dream Wall Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Express 7 Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Network Video Recorder Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Network Video Recorder G2 Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Network Video Recorder G2 Pro Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Network Video Recorder Instant Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Network Video Recorder Pro Firmware | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
| Ui | Unifi Os Server | ≤ 5.1.15 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.6 | CVSS 3.1 | High | 3.9 | 4.0 | support@hackerone.com via NIST National Vulnerability Database |
| 8.6 | CVSS 3.1 | High | — | — | hackerone via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N (score shown at the top: support@hackerone.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor file creation in web directories and paths with traversal sequences (../).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · ubiquiti inc/unifi os server, ubiquiti inc/dream machines, ubiquiti inc/enterprise fortress gateway, ubiquiti inc/dream
- SSVC assessment updated
- Record published
- CVSS changed · 8.6
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-55112 Improper Access Control in Ui Unifi Dream Machine Pro Firmware Jul 2, 2026
- High CVE-2026-54404 SQL Injection in Ui Unifi Dream Machine Beast Firmware Jul 2, 2026
- Medium CVE-2026-55110 Permissive Cross-domain Policy in Ui Unifi Os Server Jul 2, 2026
- High CVE-2026-54401 Server-Side Request Forgery (SSRF) in Ui Unifi Os Server Jul 2, 2026
- High CVE-2026-54402 Command Injection in Ui Unifi Os Server Jul 2, 2026
- Critical CVE-2026-34910 Ubiquiti UniFi OS Improper Input Validation Vulnerability KEV May 21, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-54403 is "Path Traversal in Ubiquiti Inc Cloud Gateways", rated High. It affects Cloud Gateways (Ubiquiti Inc); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.6 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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