Cyber Resilience

CVE-2026-54401

SSRF in Ui Unifi Os Server ≤ 5.1.15

SSRF
Published
02 July 2026
Modified
10 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
EPSS Score 0.0024 15th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2026-54401 is a high-severity SSRF (CWE-918) vulnerability in Ui Unifi Os Server. Its CVSS base score is 7.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

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.

CWE(s)
CWE-918

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-54403Same product: Ui Enterprise Firewall Core
CVE-2026-54404Same product: Ui Enterprise Firewall Core
CVE-2026-34911Same product: Ui Enterprise Fortress Gateway
CVE-2026-34909Same product: Ui Enterprise Fortress Gateway
CVE-2026-34910Same product: Ui Enterprise Fortress Gateway
CVE-2026-54402Same product: Ui Enterprise Firewall Core
CVE-2026-55113Same vendor: Ui
CVE-2026-55115Same vendor: Ui
CVE-2026-34908Same product: Ui Enterprise Fortress Gateway
CVE-2026-55110Same product: Ui Enterprise Firewall Core

Affected Assets

ui
unifi os server
≤ 5.1.15
ui
unifi dream machine firmware
≤ 5.1.15
ui
unifi dream machine pro firmware
≤ 5.1.15
ui
unifi dream machine special edition firmware
≤ 5.1.15
ui
unifi dream machine pro max firmware
≤ 5.1.15
ui
unifi dream machine beast firmware
≤ 5.1.15
ui
enterprise fortress gateway firmware
≤ 5.1.15
ui
unifi dream router firmware
≤ 5.1.15
ui
unifi dream wall firmware
≤ 5.1.15
ui
unifi dream router 7 firmware
≤ 5.1.15
+22 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

AC-4 Information Flow Enforcement good match

Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.

SI-10 Information Input Validation good match

Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.

SC-7 Boundary Protection partial match

Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.7 Threat intelligence partial match
prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References