# CVE-2026-31027: Memory corruption in n/a

> Remote attackers can trigger a buffer overflow in the TOTOlink A3600R router via the setAppEasyWizardConfig interface, potentially achieving arbitrary code execution or causing denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 1 Apr 2026
- **Updated:** 1 Apr 2026
- **Also known as:** GHSA-v5j6-9mr9-qwhr

## What is CVE-2026-31027?

CVE-2026-31027 is a critical memory corruption vulnerability in n/a, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

TOTOlink A3600R v5.9c.4959 contains a buffer overflow vulnerability in the setAppEasyWizardConfig interface of /lib/cste_modules/app.so. The vulnerability occurs because the rootSsid parameter is not properly validated for length, allowing remote attackers to trigger a buffer overflow, potentially leading to arbitrary code execution or denial of service.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2026-31027?

It affects 1 product.


Products: Totolink A3600r Firmware.

## How do I fix CVE-2026-31027?

No fix has been published for CVE-2026-31027 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-31027 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31027 exists.

## Other vulnerabilities in n/a

- [CVE-2022-34993](https://insights.sbomify.com/CVE-2022-34993/): Hardcoded credentials in n/a (critical 9.8)
- [CVE-2022-25078](https://insights.sbomify.com/CVE-2022-25078/): Command injection in n/a (critical 9.8)
- [CVE-2026-1686](https://insights.sbomify.com/CVE-2026-1686/): Totolink A3600R app.so setAppEasyWizardConfig buffer overflow (high 8.7)
- [CVE-2024-7174](https://insights.sbomify.com/CVE-2024-7174/): TOTOLINK A3600R cstecgi.cgi setdeviceName buffer overflow (high 8.7)
- [CVE-2024-7176](https://insights.sbomify.com/CVE-2024-7176/): TOTOLINK A3600R cstecgi.cgi setIpQosRules buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31027 and fix it if it is affected.

What it is: CVE-2026-31027 is a critical memory corruption vulnerability in n/a, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31027 exists.

Affected product: n/a. 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-2026-31027/ (Markdown: https://insights.sbomify.com/CVE-2026-31027/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31027
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31027
- OSV: https://osv.dev/vulnerability/CVE-2026-31027

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31027/
Summaries are generated and may contain mistakes; the official description above is the record.