VDB-375951 · CVE-2026-55110 · GCVE-0-2026-55110

Ubiquiti UniFi OS Server prior 5.1.19 cross-domain policy

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2	$0-$5k	0.68

Summaryinfo

A vulnerability identified as critical has been detected in Ubiquiti UniFi OS Server, Dream Machines, Enterprise Fortress Gateway, Dream Wall, Dream Routers, Express 7, Cloud Keys, Network Video Recorders, Enterprise Video Recorders, Cloud Gateways, Network Attached Storage and Enterprise Firewall Core. This issue affects some unknown processing. Performing a manipulation results in cross-domain policy. This vulnerability is identified as CVE-2026-55110. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Ubiquiti UniFi OS Server, Dream Machines, Enterprise Fortress Gateway, Dream Wall, Dream Routers, Express 7, Cloud Keys, Network Video Recorders, Enterprise Video Recorders, Cloud Gateways, Network Attached Storage and Enterprise Firewall Core. This affects some unknown functionality. The manipulation with an unknown input leads to a cross-domain policy vulnerability. CWE is classifying the issue as CWE-942. The product uses a cross-domain policy file that includes domains that should not be trusted. This is going to have an impact on integrity. The summary by CVE is:

A malicious actor who lures an authenticated user to a malicious page could exploit a Cross-Origin Resource Sharing (CORS) misconfiguration found in UniFi OS to trigger actions in UniFi OS using that user's session.

It is possible to read the advisory at community.ui.com. This vulnerability is uniquely identified as CVE-2026-55110 since 06/16/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 5.1.19 eliminates this vulnerability. The upgrade is hosted for download at community.ui.com.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Network Attached Storage Software

Vendor

Ubiquiti

Name

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (hackerone): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross-domain policy
CWE: CWE-942 / CWE-346 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Timelineinfo

06/16/2026 CVE reserved
07/02/2026 +16 days Advisory disclosed
07/02/2026 +0 days VulDB entry created
07/02/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: community.ui.com
Status: Confirmed

CVE: CVE-2026-55110 (🔒)
GCVE (CVE): GCVE-0-2026-55110
GCVE (VulDB): GCVE-100-375951

Entryinfo

Created: 07/02/2026 17:40
Changes: 07/02/2026 17:40 (64)
Complete: 🔍
Cache ID: 216::103