CVE-2026-73462 PUBLISHED

On affected platforms running Arista EOS with IGMP (Internet Group Management Protocol) snooping configured (enabled by default on all VLANs), a network-adjacent unauthenticated attacker can send malformed network packets on an affected VLAN to cause the I

Assigner: Arista
Reserved: 12.08.2026 Published: 16.09.2026 Updated: 16.09.2026

On affected platforms running Arista EOS with IGMP (Internet Group Management Protocol) snooping configured (enabled by default on all VLANs), a network-adjacent unauthenticated attacker can send malformed network packets on an affected VLAN to cause the IGMP snooping agent to terminate unexpectedly. This results in a temporary disruption of multicast traffic management, which may cause multicast traffic to be flooded to all ports of the affected VLAN until the service recovers. Repeated exploitation could result in a prolonged loss of intended multicast forwarding behavior.

CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 6.5

Attack Vector	Adjacent Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Adjacent	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Arista Networks
Product	EOS
Versions	Default: unaffected affected from 4.36.0 to 4.36.1F (incl.) affected from 4.35.0 to 4.35.5M (incl.) affected from 4.34.0 to 4.34.7.1M (incl.) affected from 4.33.0 to 4.33.8M (incl.)

Affected Configurations

IGMP snooping agent is instantiated by default on EOS. No configuration is required.

Workarounds

There is no mitigation or workaround available. Disabling IGMP snooping will NOT mitigate the issue.

Solutions

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-73462 has been fixed in the following releases:

4.36.2F and later releases in the 4.36.x train
4.35.6M and later releases in the 4.35.x train
4.34.8M and later releases in the 4.34.x train
4.33.9M and later releases in the 4.33.x train

Credits

This issue was discovered internally by Arista. finder

References

https://www.arista.com/en/support/advisories-notices/security-advisory/24715-security-advisory-0159

Problem Types

CWE-125 Out-of-bounds Read CWE

Impacts

CAPEC-540 Over-read Buffers