Authentication bypass using an alternate path or channel in Arista Extensible Operating System (EOS) - CVE-2026-12546
Published: June 24, 2026
Vulnerability identifier: #VU135099
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-12546
CWE-ID: CWE-288
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Arista Networks
Affected software:
Arista Extensible Operating System (EOS)
Arista Extensible Operating System (EOS)
Detailed vulnerability description
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.
How to mitigate CVE-2026-12546
Install security update from vendor's website.