Is CVE-2020-26139 actively exploited?

No active exploitation of CVE-2020-26139 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2020-26139 be exploited remotely?

Partially. CVE-2020-26139 requires adjacent network access (same network segment) to exploit.

What is the CVSS score of CVE-2020-26139?

CVE-2020-26139 has a CVSS score of 5.3 (MEDIUM).

HOME VULNERABILITIESCVE-2020-26139

MEDIUM

CVE-2020-26139

CWE-287Published: May 11, 2021· Updated: Jun 17, 2026

5.3

CVSS v3.1

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.

NVD Source

Technical Analysis

CVE-2020-26139 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.3.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorAdjacent

Attack ComplexityHigh

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

arista30 product(s)

c-100 firmwarec-100c-110 firmwarec-110c-120 firmwarec-120c-130 firmwarec-130c-200 firmwarec-200c-230 firmwarec-230+18

Cisco256 product(s)

1100 firmware11001100-4p firmware1100-4p1100-8p firmware1100-8p1101-4p firmware1101-4p1109-2p firmware1109-2p1109-4p firmware1109-4p+244

Debian1 product(s)

debian linux

intel42 product(s)

ac 8260 firmwareac 8260ac 8265 firmwareac 8265ac 9260 firmwareac 9260ac 9560 firmwareac 9560killer ac 1550 firmwarekiller ac 1550killer wi-fi 6 ax1650 firmwarekiller wi-fi 6 ax1650+30

netbsd1 product(s)

netbsd

Source: NVD CPE · 330 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Exploit-DB

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

PacketStorm

Security advisories & exploits

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://cert-portal.siemens.com/productcert/pdf/ssa-913875.pdf

ADVISORYhttp://www.openwall.com/lists/oss-security/2021/05/11/12

ADVISORYhttps://github.com/vanhoefm/fragattacks/blob/master/SUMMARY.md

ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

ADVISORYhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wifi-faf-22epcEWu

ADVISORYhttps://www.arista.com/en/support/advisories-notices/security-advisories/12602-security-advisory-63

ADVISORYhttps://www.fragattacks.com

ADVISORYhttp://www.openwall.com/lists/oss-security/2021/05/11/12

ADVISORYhttps://github.com/vanhoefm/fragattacks/blob/master/SUMMARY.md

ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/06/msg00019.html

ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

ADVISORYhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wifi-faf-22epcEWu

ADVISORYhttps://www.arista.com/en/support/advisories-notices/security-advisories/12602-security-advisory-63

ADVISORYhttps://www.fragattacks.com

News & Research Mentioning CVE-2020-26139

Siemens SCALANCE

CISA Alerts· Apr 21, 2026

View CSAF Summary SCALANCE W-700 IEEE 802.11n family before V6.6.0 are affected by multiple vulnerabilities. Siemens has released a new version for SCALANCE W-700 IEEE 802.11n family and recommends to update to the latest version. The following versions of Siemens SCALANCE are affected: SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AA0) vers:intdot/<6.6.0 (CVE-2020-24588, CVE-2020-26139, CVE-2020-26140, CVE-2020-26141, CVE-2020-26143, CVE-2020-26144, CVE-2020-26146, CVE-2020-26147, CVE-2021-3712, CVE-2022-0778, CVE-2022-31765, CVE-2022-36323, CVE-2022-36324, CVE-2022-36325, CVE-2023-44373) SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AB0) vers:intdot/<6.6.0 (CVE-2020-24588, CVE-2020-26139, CVE-2020-26140, CVE-2020-26141, CVE-2020-26143, CVE-2020-26144, CVE-2020-26146 [xlite_meta score:63 src:CISA Alerts xlite_fp:97dcbf6085fea11c4ef39ae2fb1a0fa497a23c7dd709ebf0d40bfba60bdeefae]