CVE-2026-75943

Brief ACL bypass during supplicant removal

Published Sep 14, 2026 · Updated Sep 14, 2026

Incomplete cleanup in Arista EOS allows remote authenticated users on an adjacent segment to bypass per-supplicant ACLs. When EOS removes an authenticated 802.1X supplicant after clear dot1x host all or a timeout, it leaves traffic briefly unfiltered instead of maintaining ACL enforcement throughout cleanup. The issue requires authenticator mode, automatic port control, and an ACL assigned through RADIUS; bypass lasts milliseconds to seconds and affects access-control integrity only.

CVSS severity2.1
Low
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incomplete cleanup in Arista EOS allows remote authenticated users on an adjacent segment to bypass per-supplicant ACLs. When EOS removes an authenticated 802.1X supplicant after clear dot1x host all or a timeout, it leaves traffic briefly unfiltered instead of maintaining ACL enforcement throughout cleanup. The issue requires authenticator mode, automatic port control, and an ACL assigned through RADIUS; bypass lasts milliseconds to seconds and affects access-control integrity only.

The record

CVE
CVE-2026-75943
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Arista Networks
Product
Arista EOS
Classifications
CWE-459, T1562.004
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0.0 <=4.33.9M
  2. Affected versionversion=4.34.0 <=4.34.7.1M
  3. Affected versionversion=4.35.0 <=4.35.5M
  4. Affected versionversion=4.36.0 <=4.36.1F

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Arista Networks · Arista EOSversion=0.0.0 <=4.33.9M; version=4.34.0 <=4.34.7.1M; version=4.35.0 <=4.35.5M; version=4.36.0 <=4.36.1F

Published CVSS scores

2.1Arista NetworksCVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
2.6Arista NetworksCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-459Incomplete Cleanup
T1562.004Disable or Modify System Firewall

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo