# CVE-2026-15579: Memory corruption in TN-4500B Series

> Remote attackers can cause a denial of service on Moxa Ethernet switches by sending overly long input during web login, triggering a buffer overflow.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-hv3x-fr88-gcjp

## What is CVE-2026-15579?

CVE-2026-15579 is a high-severity memory corruption vulnerability in Moxa TN-4500B Series, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An out-of-bounds write vulnerability exists in some of the Ethernet switches because of improper validation of the username field length during Web login processing. This may allow a remote attacker to submit a specially crafted overly long input, triggering a buffer overflow that can cause the authentication process to crash and result in a Denial of Service (DoS) attack.

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

## Which versions are affected by CVE-2026-15579?


## How do I fix CVE-2026-15579?

No fix has been published for CVE-2026-15579 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15579 being exploited?

There is no known exploitation of CVE-2026-15579 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15579 and fix it if it is affected.

What it is: CVE-2026-15579 is a high-severity memory corruption vulnerability in Moxa TN-4500B Series, published on 18 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-2026-15579 in the wild and no public exploit code.

Affected product: Moxa TN-4500B Series. 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-2026-15579/ (Markdown: https://insights.sbomify.com/CVE-2026-15579/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15579
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15579
- OSV: https://osv.dev/vulnerability/CVE-2026-15579

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15579/
Summaries are generated and may contain mistakes; the official description above is the record.