# CVE-2026-77555: Memory corruption in Cloud Gateways

> A remote attacker can cause a denial of service on UniFi network devices via an out-of-bounds write vulnerability.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-gx3q-h4jp-wj72

## What is CVE-2026-77555?

CVE-2026-77555 is a high-severity memory corruption vulnerability in Ubiquiti Inc Cloud Gateways, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-77555?


## How do I fix CVE-2026-77555?

No fix has been published for CVE-2026-77555 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77555 being exploited?

There is no known exploitation of CVE-2026-77555 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77555 and fix it if it is affected.

What it is: CVE-2026-77555 is a high-severity memory corruption vulnerability in Ubiquiti Inc Cloud Gateways, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-77555 in the wild and no public exploit code.

Affected product: Ubiquiti Inc Cloud Gateways. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-77555/ (Markdown: https://insights.sbomify.com/CVE-2026-77555/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77555
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77555
- OSV: https://osv.dev/vulnerability/CVE-2026-77555

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77555/
Summaries are generated and may contain mistakes; the official description above is the record.