Improper input validation in Arista Networks Eos

CVE-2026-77190

On affected platforms running Arista EOS, an unauthenticated attacker who is network-adjacent to the switch and able to connect to a device with PIM Sparse Mode and MLAG configured, can send malformed messages that cause the Pimsm agent to terminate unexpectedly. The Pimsm agent is automatically restarted, but repeated attacks can cause the agent to restart continuously, resulting in a sustained denial of service.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77190?
CVE-2026-77190 is a medium-severity vulnerability in Arista Networks Eos, classified under Improper Input Validation. CVSS score: 6.5/10. Published 2026-09-16.
How severe is CVE-2026-77190?
Medium severity. CVSS v3 base score is 6.5 out of 10.