CVE-2026-121289

critical

Description

On affected platforms running Arista EOS with BGP configured, a specially crafted packet can cause the BGP agent to crash. Successful exploitation causes the BGP agent process to terminate, resulting in the loss of all BGP sessions on the affected device and possible disruption to network routing until the process recovers. Due to the nature of the vulnerability, it may also be possible for a sophisticated attacker to achieve arbitrary code execution, which could compromise the confidentiality and integrity of the affected system.

References

https://www.arista.com/en/support/advisories-notices/security-advisory/25030-security-advisory-0208

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-122810

Details

Source: Mitre, NVD

Published: 2026-11-10

Updated: 2026-11-13

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base Score: 9.3

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

Severity: Critical

EPSS

EPSS: 0.00644