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Arista NetworksCVE-2026-77190

Arista Networks EOS: denial of service

Medium6.0CVE-2026-77190 · Published Sep 16, 2026

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.

Arista Networks advisory

Affected versions

PackageAffectedFixed in
EOS
Product
>= 4.36.0F, <= 4.36.1FNo fix yet
>= 4.35.0F, <= 4.35.5MNo fix yet
>= 4.34.2F, <= 4.34.7MNo fix yet
Details and references
CVSS 4.0
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-20

More Arista Networks advisories

All Arista Networks
Advisory
Arista Networks EOS: remote code execution
Critical9.2Sep 16
Arista Networks EOS: secrets in logs
Medium6.0Sep 16
Arista Networks EOS: out-of-bounds read
High7.1Sep 16
Arista Networks EOS: secrets in logs
Low2.1Sep 16
Arista Networks EOS: denial of service
Medium5.3Sep 16
Arista Networks VeloCloud Edge: missing authentication
High8.7Sep 16

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