# CVE-2026-0839: UTT 进取 520W APSecurity strcpy buffer overflow

> Remote attackers can trigger a buffer overflow in the APSecurity component via the wepkey1 argument, potentially leading to code execution or service disruption.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jan 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-55hm-v7vp-29ch

## What is CVE-2026-0839?

CVE-2026-0839 is a high-severity memory corruption vulnerability in UTT 进取 520W, published on 11 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A weakness has been identified in UTT 进取 520W 1.7.7-180627. Affected is the function strcpy of the file /goform/APSecurity. Executing a manipulation of the argument wepkey1 can lead to buffer overflow. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-0839?

It affects 1 product.


Products: Utt 520w Firmware.

## How do I fix CVE-2026-0839?

No fix has been published for CVE-2026-0839 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-0839 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0839 exists.

## Other vulnerabilities in UTT 进取 520W

- [CVE-2026-31059](https://insights.sbomify.com/CVE-2026-31059/): Command injection in n/a (critical 9.8)
- [CVE-2026-2071](https://insights.sbomify.com/CVE-2026-2071/): UTT 进取 520W formP2PLimitConfig strcpy buffer overflow (high 8.7)
- [CVE-2026-2066](https://insights.sbomify.com/CVE-2026-2066/): UTT 进取 520W formIpGroupConfig strcpy buffer overflow (high 8.7)
- [CVE-2026-2067](https://insights.sbomify.com/CVE-2026-2067/): UTT 进取 520W formTimeGroupConfig strcpy buffer overflow (high 8.7)
- [CVE-2026-2068](https://insights.sbomify.com/CVE-2026-2068/): UTT 进取 520W formSyslogConf strcpy buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0839 and fix it if it is affected.

What it is: CVE-2026-0839 is a high-severity memory corruption vulnerability in UTT 进取 520W, published on 11 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0839 exists.

Affected product: UTT 进取 520W. 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-2026-0839/ (Markdown: https://insights.sbomify.com/CVE-2026-0839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0839
- OSV: https://osv.dev/vulnerability/CVE-2026-0839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0839/
Summaries are generated and may contain mistakes; the official description above is the record.