# CVE-2020-26139: Missing authorization in n/a

> NetBSD kernel allows unauthenticated EAPOL frame forwarding, enabling denial-of-service attacks against Wi-Fi clients and facilitating further exploitation.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 14 Apr 2026
- **Also known as:** 2860248, 2867013, 2868054, 2888227, 2888467, 2942096, 2943789, A-177911151, ASB-A-177911151, DEBIAN-CVE-2020-26139, GHSA-326j-j9mx-gf84, UBUNTU-CVE-2020-26139

## What is CVE-2020-26139?

CVE-2020-26139 is a medium-severity missing authorization vulnerability in Debian Debian Linux, 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 kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2020-26139?

It affects 166 products.


Products: 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, Cisco 1109-2p Firmware and 146 more.

## How do I fix CVE-2020-26139?

Apply the vendor's patch.

## Is CVE-2020-26139 being exploited?

There is no known exploitation of CVE-2020-26139 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2020-26144](https://insights.sbomify.com/CVE-2020-26144/): Other in n/a (medium 6.5)
- [CVE-2020-26146](https://insights.sbomify.com/CVE-2020-26146/): Information disclosure in n/a (medium 5.3)
- [CVE-2020-24588](https://insights.sbomify.com/CVE-2020-24588/): The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that the (low 3.5)
- [CVE-2020-24587](https://insights.sbomify.com/CVE-2020-24587/): The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that all (low 2.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26139 and fix it if it is affected.

What it is: CVE-2020-26139 is a medium-severity missing authorization vulnerability in Debian Debian Linux, 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-2020-26139 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2020-26139/ (Markdown: https://insights.sbomify.com/CVE-2020-26139/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26139
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26139
- OSV: https://osv.dev/vulnerability/CVE-2020-26139

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-26139/
Summaries are generated and may contain mistakes; the official description above is the record.