Intel

CVE-2026-77558

UniFi: Out-of-bounds Read (CVE-2026-77558)

highEPSS 0.5%

Description

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

Source: BSI CSAFBSI WID Portalcvelistv5NVD (NIST)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

UbiquitiUniFi
Gateways <5.1.26

Metrics

XIEM Effective CVSS
7.5
Source: cna-v3
EPSS percentile
37.9 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
—
Show all metrics
Severity
high
Priority score
79.01
Exploit maturity
no public PoC known
CVSS v3
7.5
EPSS score
0.5 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-09-22 18:43 UTC
CWE
CWE-125

Weakness classes (CWE)

  • CWE-125Base

    Out-of-bounds Read

    The product reads data past the end, or before the beginning, of the intended buffer.

    cwe.mitre.org →

References & sources

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-09-22 20:17 UTC· 134c704f-9b21-4f2e-91b3-4a467353bcc0
    • SSVC: {"id":"CVE-2026-77558","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technical…
  2. New CVE Received2026-09-22 19:16 UTC· fe490ce8-0395-4072-90d8-2707e1bdf984
    • Description: A malicious actor with access to the network could exploit an Out-of-bounds Read vulnerability found in certain UniFi gateway devices to execute a Denial of Service (DoS) attack on the device.
    • CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    • CWE: CWE-125
    • Affected: New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/77xxx/CVE-2026-77558.json">CVE-2026-77558</a>