CVE-2026-77190

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Arista NetworksEOS4.36.0F <= 4.36.1Faffected
Arista NetworksEOS4.35.0F <= 4.35.5Maffected
Arista NetworksEOS4.34.2F <= 4.34.7Maffected

Weaknesses

  • CWE-20: CWE-20 Improper Input Validation

Workarounds

There is no mitigation or workaround available.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References