CVE-2023-5502Network attack vector

Unauthenticated routed VLAN access via 802.1X bypass

Published Jun 4, 2026 · Updated Jun 4, 2026

Authentication bypass in Arista EOS 4.17.0 through 4.31.0F allows attackers to reach a routed access VLAN without completing 802.1X. Arista has not published the internal mechanism that lets traffic from an unauthenticated supplicant reach the routed access VLAN. Exploitation requires 802.1X on an access or trunk port, IP routing on its access VLAN, and specified host-mode or MAC-based authentication settings.

CVSS severity8.2
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Arista EOS 4.17.0 through 4.31.0F allows attackers to reach a routed access VLAN without completing 802.1X. Arista has not published the internal mechanism that lets traffic from an unauthenticated supplicant reach the routed access VLAN. Exploitation requires 802.1X on an access or trunk port, IP routing on its access VLAN, and specified host-mode or MAC-based authentication settings.

The record

CVE
CVE-2023-5502
Published
Jun 4, 2026
Updated
Jun 4, 2026
Vendor
Arista Networks
Product
Arista Extensible Operating System (EOS)
Classifications
CWE-287, CAPEC-115
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 4, 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=4.24.0 <=4.24.11M
  2. Affected versionversion=4.25.0 <=4.25.11M
  3. Affected versionversion=4.26.0 <=4.26.11M
  4. Affected versionversion=4.27.0 <=4.27.11M
  5. Affected versionversion=4.28.0 <=4.28.8M
  6. Affected versionversion=4.29.0 <=4.29.6M
  7. Affected versionversion=4.30.0 <=4.30.4M
  8. Affected versionversion=4.31.0 <=4.31.0F

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Arista Networks · Arista Extensible Operating System (EOS)version=4.24.0 <=4.24.11M; version=4.25.0 <=4.25.11M; version=4.26.0 <=4.26.11M; version=4.27.0 <=4.27.11M; version=4.28.0 <=4.28.8M; version=4.29.0 <=4.29.6M; version=4.30.0 <=4.30.4M; version=4.31.0 <=4.31.0F

Published CVSS scores

8.2Arista NetworksCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
5.9Arista NetworksCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CAPEC-115Authentication Bypass

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

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Your stack

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