SB2026062433 - Security restrictions bypass in Arista EOS

Description

This security bulletin contains information about 1 vulnerability.

1) Authentication bypass using an alternate path or channel (CVE-ID: CVE-2026-12546)

CWE-ID: CWE-288 - Authentication Bypass Using an Alternate Path or Channel

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to bypass the intended redirection policy or cause localized CPU overhead.

The vulnerability exists due to authentication bypass using an alternate path or channel in next-hop redirection features when processing IP packets that require exception handling and match an active redirection policy. A remote user can send specially crafted mtu-exceeding packets to bypass the intended redirection policy or cause localized CPU overhead.

Exploitation requires one of the affected redirection features to be configured with a next-hop or redirect action, and only certain packet classes that meet distinct exception-processing criteria can trigger the issue.

Remediation

Install update from vendor's website.

References

• https://www.arista.com/en/support/advisories-notices/security-advisory/24111-security-advisory-0142