CVE-2024-27891: On affected platforms running Arista EOS with MACsec and egress ACLs configured on the same interfaces, the ACL policies may not be enforced for packets egressing on those ports.

Published Jun 4, 2026

Updated

On affected platforms running Arista EOS with MACsec and egress ACLs configured on the same interfaces, the ACL policies may not be enforced for packets egressing on those ports. This can cause outgoing packets to incorrectly be allowed or denied.

Affected Software

1 affected component

Arista Networks EOS

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Arista EOS to a version that resolves this vulnerability.
Fixed in 4.28.11M
Upgrade
Upgrade Arista EOS to a version that resolves this vulnerability.
Fixed in 4.29.8M
Upgrade
Upgrade Arista EOS to a version that resolves this vulnerability.
Fixed in 4.30.7M
Upgrade
Upgrade Arista EOS to a version that resolves this vulnerability.
Fixed in 4.31.3M
Upgrade
Upgrade Arista EOS to a version that resolves this vulnerability.
Fixed in 4.32.1F

Event History

Jun 4, 2026

CVE Published

via MITRE·10:08 PM

Data Sourced

via MITRE·10:08 PM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·11:16 PM

DescriptionSeverityWeakness

Frequently Asked Questions

What is the severity of CVE-2024-27891?

The severity of CVE-2024-27891 is medium with a score of 5.3.

What platforms are affected by CVE-2024-27891?

CVE-2024-27891 affects platforms running Arista EOS with MACsec and egress ACLs configured on the same interfaces.

How do I fix CVE-2024-27891?

To fix CVE-2024-27891, upgrade to a remediated software version of Arista EOS at your earliest convenience.

What issues does CVE-2024-27891 cause?

CVE-2024-27891 can cause ACL policies to not be enforced for packets egressing on affected ports, leading to incorrect packet handling.

When was CVE-2024-27891 published?

CVE-2024-27891 was published on June 4, 2026.