# CVE-2026-71958: D-Link DWR-M961 Buffer Overflow via quicksetup.cgi

> Remote attackers can execute arbitrary commands or crash D-Link DWR-M961 routers via buffer overflow in quicksetup.cgi.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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:** 8 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-8mjf-qrcg-h2cj

## What is CVE-2026-71958?

CVE-2026-71958 is a critical memory corruption vulnerability in D-Link Corporation DWR-M961, published on 8 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

D-Link DWR-M961 devices with hardware version C1 and software version 1.1.2_C1_202602110044 contain a buffer overflow vulnerability in the quicksetup.cgi interface. A remote attacker can write overly long strings to the test4, ssid2, and username fields and execute arbitrary commands by crafting a specific payload, or cause the device to crash.

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

## Which versions are affected by CVE-2026-71958?


## How do I fix CVE-2026-71958?

No fix has been published for CVE-2026-71958 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71958 being exploited?

There is no known exploitation of CVE-2026-71958 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71958 and fix it if it is affected.

What it is: CVE-2026-71958 is a critical memory corruption vulnerability in D-Link Corporation DWR-M961, published on 8 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-2026-71958 in the wild and no public exploit code.

Affected product: D-Link Corporation DWR-M961. 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-2026-71958/ (Markdown: https://insights.sbomify.com/CVE-2026-71958/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71958
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71958
- OSV: https://osv.dev/vulnerability/CVE-2026-71958

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71958/
Summaries are generated and may contain mistakes; the official description above is the record.