CVE-2026-121295 PUBLISHED

Security Advisory 0223

Assigner: Arista
Reserved: 03.11.2026 Published: 10.11.2026 Updated: 10.11.2026

On affected platforms running Arista EOS configured as S-BFD peers, an unauthenticated attacker could send a crafted S-BFD PDU to an initiator device. This crafted PDU could cause the kernel on the initiator device to crash, resulting in an unexpected device reboot.

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS Score: 8.6

Attack Vector	Network	Scope	Changed
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:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
CVSS Score: 9.2

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

CVSS 4.0

Product Status

Vendor	Arista Networks
Product	EOS
Versions	Default: unaffected affected from 4.36.0F to 4.36.2F (incl.) affected from 4.35.0F to 4.35.6M (incl.) affected from 4.34.0F to 4.34.8M (incl.) affected from 4.33.0F to 4.33.10M (incl.) affected from 4.32.0F to 4.33.0F (excl.) affected from 1.0.0 to 4.32.0F (excl.)

Affected Configurations

CVE-2026-121294: switch#show running-config section sbfd router bfd sbfd reflector local-discriminator <DISC> proxy

CVE-2026-121295: switch#show running-config section sbfd router bfd sbfd initiator measurement delay round-trip

References

https://www.arista.com/en/support/advisories-notices/security-advisory/25045-security-advisory-0223

Problem Types

CWE-1284 Improper Validation of Specified Quantity in Input CWE

Impacts

CAPEC-100 Overflow Buffers