# CVE-2026-74843: Wavlink WN531P3/WN535M1 Export Pingortrace CGI export_pingortrace.cgi strcpy stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the export_pingortrace.cgi component via the HTTP_COOKIE argument, potentially leading to code execution or denial of service.

- **Severity:** Critical 10.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** GHSA-p9ff-qq24-ccr6

## What is CVE-2026-74843?

CVE-2026-74843 is a critical memory corruption vulnerability in Wavlink WN531P3, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was determined in Wavlink WN531P3 and WN535M1 V250922. Affected by this vulnerability is the function strcpy of the file /etc/lighttpd/www/cgi-bin/export_pingortrace.cgi of the component Export Pingortrace CGI. Executing a manipulation of the argument HTTP_COOKIE can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-74843?


## How do I fix CVE-2026-74843?

No fix has been published for CVE-2026-74843 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-74843 being exploited?

There is no known exploitation of CVE-2026-74843 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74843 and fix it if it is affected.

What it is: CVE-2026-74843 is a critical memory corruption vulnerability in Wavlink WN531P3, published on 17 Aug 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-2026-74843 in the wild and no public exploit code.

Affected product: Wavlink WN531P3. 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-2026-74843/ (Markdown: https://insights.sbomify.com/CVE-2026-74843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74843
- OSV: https://osv.dev/vulnerability/CVE-2026-74843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74843/
Summaries are generated and may contain mistakes; the official description above is the record.