Out-of-Bounds Write Flaw in UniFi Gateway Devices from Ubiquiti Networks
CVE-2026-77555

7.5HIGH

Key Information:

Vendor

Ubiquiti Inc

Status
Dream Machines
Enterprise Firewalls
Dream Routers
Cloud Gateways
Vendor
CVE Published:
22 September 2026

What is CVE-2026-77555?

A vulnerability exists in specific UniFi gateway devices that allows a malicious actor with network access to perform an Out-of-Bounds Write. This flaw could be exploited to execute a Denial of Service (DoS) attack, potentially disrupting the device's functionality and affecting the overall network performance. Users are advised to review the security measures recommended by Ubiquiti Networks to mitigate such risks.

Affected Version(s)

Cloud Gateways 0 < 5.1.31

Dream Machines 0 < 5.1.31

Dream Routers 0 < 5.1.31

References

https://community.ui.com/releases/Security-Advisory-Bulle...

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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