CVE-2026-77190

medium

Assigned by CNA: arista

Published 2026-09-16 · Modified 2026-09-16

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CVSS v3

6.5

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4 NEW

6.0

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

VIR risk

6.5

Description

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.

Predictions

Exploit likelihood

65%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

https://www.arista.com/en/support/advisories-notices/security-advisory/24733-security-advisory-0177

CWEs

CWE-20

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.