Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:C) | Scope changed: impact spreads beyond the component |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:N) | No integrity impact |
| Availability (A:N) | No availability impact |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
About Ui Unifi Os Server
CVE-2026-54401 affects Ui Unifi Os Server, a product from Ui. Before acting, confirm where Ui Unifi Os Server runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: A malicious actor with access to the network and low privileges could exploit a Server-Side Request Forgery (SSRF) to escalate privileges within such UniFi OS devices or instances.
The weakness class is Server Side Request Forgery. The server can be made to send requests to internal or arbitrary systems.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Ui Unifi Os Server |
| Affected versions | Unifi Os Server up to and including 5.1.15; Unifi Dream Machine Firmware up to and including 5.1.15; Unifi Dream Machine Pro Firmware up to and including 5.1.15; Unifi Dream Machine Special Edition Firmware up to and including 5.1.15; Unifi Dream Machine Pro Max Firmware up to and including 5.1.15; Unifi Dream Machine Beast Firmware up to and including 5.1.15; Enterprise Fortress Gateway Firmware up to and including 5.1.15; Unifi Dream Router Firmware up to and including 5.1.15; Unifi Dream Wall Firmware up to and including 5.1.15; Unifi Dream Router 7 Firmware up to and including 5.1.15; Unifi Express 7 Firmware up to and including 5.1.15; Unifi Cloudkey Firmware up to and including 5.1.15 |
| Published | Jul 2, 2026 |
| Last modified | Jul 10, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | support@hackerone.com |
How to detect it
- Inventory every instance of Ui Unifi Os Server and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Ui Unifi Os Server named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Ui Unifi Os Server to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-918: Server Side Request Forgery More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
A malicious actor with access to the network and under certain network configurations could exploit an Improper Access Control vulnerability found in certain devices running UniFi OS to make unauthorized changes to such UniFi OS devices.
A malicious actor with access to the network and low privileges could exploit a Server-Side Request Forgery (SSRF) in UniFi Protect Application to escalate privileges on the host device.
A malicious actor with access to the network and low privileges and under certain conditions could exploit an Improper Access Control vulnerability found in UniFi OS with UniFi Protect Application to escalate privileges on the host device.
A malicious actor with access to the network and under certain conditions could exploit an Improper Initialization vulnerability found in UniFi Protect Application to bypass authentication in UniFi Protect Cameras.
A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in UniFi Protect Application to bypass authentication for data streaming.
A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi OS to execute a Command Injection on the host device.
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