CVE-2026-77555

Description

A malicious actor with access to the network could exploit an Out-of-bounds Write vulnerability found in certain UniFi gateway devices to execute a Denial of Service (DoS) attack on the device.

Overview

State: PUBLISHED
Assigner (CNA): Ubiquiti
CVSS severity: HIGH
CVSS score: 7.5 / 10
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Effective score: 7.5 / 10 HIGH source: CNA overview
CWE(s): CWE-787
Reserved: 2026-08-20
Published: 2026-09-22 18:38 UTC
Last updated: 2026-09-22 19:32 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/77xxx/CVE-2026-77555.json
Linked Threat: CVE-2026-77555 — CVE-2026-77555

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-22 19:16:51 UTC
NVD last modified: 2026-09-22 20:17:08 UTC
NVD CVSS v3.1: 7.5 / 10 HIGH source: fe490ce8-0395-4072-90d8-2707e1bdf984
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 3.6 / 10

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-84754
Assigner: Ubiquiti
Published: Sep 22, 2026, 6:38:20 PM
Updated: Sep 22, 2026, 7:32:56 PM
EUVD base score (CVSS 3.1): 7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EUVD-reported EPSS: 0.0000
Vendors: Ubiquiti Inc
Products: Dream Routers (0 <5.1.31)

Enterprise Firewalls (0 <5.1.31)

express (0 <4.0.21)

Express 7 (0 <5.1.31)

Dream Machines (0 <5.1.31)

Dream Wall (0 <5.1.31)

UniFi Gateways (0 <5.1.26)

Cloud Gateways (0 <5.1.31)
Aliases: GHSA-gx3q-h4jp-wj72

ENISA description: A malicious actor with access to the network could exploit an Out-of-bounds Write vulnerability found in certain UniFi gateway devices to execute a Denial of Service (DoS) attack on the device.

EUVD references (1)

https://community.ui.com/releases/Security-Advisory-Bulletin-069-069/07e367a7-edec-4d85-a058-f97e5ce9ac9c

Affected products (8)

Vendor	Product	Versions	Platforms
Ubiquiti Inc	Dream Machines	`0` (affected)	—
Ubiquiti Inc	Enterprise Firewalls	`0` (affected)	—
Ubiquiti Inc	Dream Routers	`0` (affected)	—
Ubiquiti Inc	Cloud Gateways	`0` (affected)	—
Ubiquiti Inc	Dream Wall	`0` (affected)	—
Ubiquiti Inc	Express	`0` (affected)	—
Ubiquiti Inc	Express 7	`0` (affected)	—
Ubiquiti Inc	UniFi Gateways	`0` (affected)	—

Vendor references (1)

References embedded in the original CVE record by the assigning CNA.

https://community.ui.com/releases/Security-Advisory-Bulletin-069-069/07e367a7-edec-4d85-a058-f97e5ce9ac9c

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (1)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://community.ui.com/releases/Security-Advisory-Bulletin-069-069/07e367a7-edec-4d85-a058-f97e5ce9ac9c fe490ce8-0395-4072-90d8-2707e1bdf984

Remediations (10)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CVE-2026-18556 / CVE-2026-18577 - Arctic Wolf

web:arcticwolf.com

Learn how to protect N-able N-central from active exploitation of CVE - 2026 -18556 and CVE - 2026 -18577 with patching, threat hunting, and mitigation guidance.

2026-09-23 15:15 UTC
Ubiquiti patches three max‑severity UniFi vulnerabilities: CVE‑2026 ...

web:blog.toolslib.net

Ubiquiti patched three max‑severity UniFi vulnerabilities (CVE‑2026‑77537, CVE‑2026‑77550, CVE‑2026‑77554). Learn what's affected, why it matters, and the updates to apply now.

2026-09-23 15:15 UTC
August 28 Advisory: Ubiquiti Security Advisory Bulletin Discloses 21 ...

web:censys.com

A Ubiquiti security advisory bulletin discloses 22 vulnerabilities, 21 of which are critical, including CVE - 2026 -77550, CVE - 2026 -77549, and CVE - 2026 -77550.

2026-09-23 15:15 UTC
Nvd-cve-2026-77554

web:nvd.nist.gov

HEADQUARTERS 100 Bureau Drive Gaithersburg, MD 20899 (301) 975-2000 Webmaster | Contact Us | Our Other Offices

2026-09-23 15:15 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-23 15:15 UTC
March 10, 2026—Hotpatch KB5079420 (OS Builds 26200.7979 and 26100.7979 ...

web:support.microsoft.com

This Hotpatch update for Windows 11, version 25H2 and 24H2 (KB5079420), improves functionality, performance, and reliability. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of ...

2026-09-23 15:15 UTC
SAP Security Patch Day - June 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 9th of June 2026 , SAP security patch day saw the release of 15 new security notes.

2026-09-23 15:15 UTC
CVE-2026-77555 - vulnerability database | Vulners.com

web:vulners.com

CVE-2026-77555 🗓️ 22 Sep 2026 11:38:20 Reported by Ubiquiti Type cve 🔗 web.nvd.nist.gov 👁 5 Views

2026-09-23 15:15 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-09-23 15:15 UTC
CVE-2026-77555 | Tenable®

web:www.tenable.com

A malicious actor with access to the network could exploit an Out-of-bounds Write vulnerability found in certain UniFi gateway devices to execute a Denial of Service (DoS) attack on the device.

2026-09-23 15:15 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-77555.json.

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