# CVE-2020-26140: Security feature bypass in n/a

> The ALFA Wi-Fi driver accepts plaintext frames in protected networks, allowing attackers to inject arbitrary data frames regardless of network configuration.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 May 2021
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-px4f-q3pw-j682, ROOT-OS-UBUNTU-2204-CVE-2020-26140, UBUNTU-CVE-2020-26140

## What is CVE-2020-26140?

CVE-2020-26140 is a medium-severity vulnerability in Siemens Scalance W1750d Firmware, published on 11 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in the ALFA Windows 10 driver 6.1316.1209 for AWUS036H. The WEP, WPA, WPA2, and WPA3 implementations accept plaintext frames in a protected Wi-Fi network. An adversary can abuse this to inject arbitrary data frames independent of the network configuration.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2020-26140?

It affects 194 products.


Products: Alfa Awus036h Firmware, Arista C-100 Firmware, Arista C-110 Firmware, Arista C-120 Firmware, Arista C-130 Firmware, Arista C-200 Firmware, Arista C-230 Firmware, Arista C-235 Firmware, Arista C-250 Firmware, Arista C-260 Firmware, Arista C-65 Firmware, Arista C-75 Firmware, Arista O-105 Firmware, Arista O-90 Firmware, Arista W-118 Firmware, Arista W-68 Firmware, Cisco 1100-4p Firmware, Cisco 1100-8p Firmware, Cisco 1100 Firmware, Cisco 1101-4p Firmware and 174 more.

## How do I fix CVE-2020-26140?

Upgrade to a fixed version.

## Is CVE-2020-26140 being exploited?

There is no known exploitation of CVE-2020-26140 in the wild and no public exploit code.

## Other vulnerabilities in Siemens Scalance W1750d Firmware

- [CVE-2020-26141](https://insights.sbomify.com/CVE-2020-26141/): Security feature bypass in n/a (medium 6.5)
- [CVE-2020-26143](https://insights.sbomify.com/CVE-2020-26143/): Security feature bypass in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26140 and fix it if it is affected.

What it is: CVE-2020-26140 is a medium-severity vulnerability in Siemens Scalance W1750d Firmware, published on 11 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-26140 in the wild and no public exploit code.

Affected product: Siemens Scalance W1750d Firmware. 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-2020-26140/ (Markdown: https://insights.sbomify.com/CVE-2020-26140/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26140
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26140
- OSV: https://osv.dev/vulnerability/CVE-2020-26140

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26140/
Summaries are generated and may contain mistakes; the official description above is the record.