What is CVE-2026-121294?

CVE-2026-121294 is a medium-severity vulnerability in Arista Networks Eos, classified under Improper Validation of Specified Quantity in Input. CVSS score: 5.3/10. Published 2026-11-10.

How severe is CVE-2026-121294?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Arista Networks Eos

CVE-2026-121294

On affected platforms running Arista EOS with a S-BFD reflector proxy configured, an unauthenticated attacker could send a crafted S-BFD Protocol Data Unit (PDU) that might cause the device to temporarily cease reflecting S-BFD packets, potentially resulting in S-BFD session timeouts.

Published 2026-11-10.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Arista Networks Eos

Weakness classification (CWE)

CWE-1284 — Improper Validation of Specified Quantity in Input

References

www.arista.com/en/support/advisories-notices/security-advisory/25045-security-a… (vendor-advisory)

Frequently asked questions

What is CVE-2026-121294?: CVE-2026-121294 is a medium-severity vulnerability in Arista Networks Eos, classified under Improper Validation of Specified Quantity in Input. CVSS score: 5.3/10. Published 2026-11-10.
How severe is CVE-2026-121294?: Medium severity. CVSS v3 base score is 5.3 out of 10.