by Kastro
Paper/Archive/CVE-2026-121289

CVE-2026-121289

Arista Networks EOS — Security Advisory 0208

CVSS 9.8
critical.is priorityof 100
29
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
EOS4.36.0F – 4.36.2F–CNA
EOS4.35.0F – 4.35.6M–CNA
EOS4.34.0F – 4.34.8M–CNA
EOS4.33.0F – 4.33.10M–CNA
EOS4.25.1F – < 4.33.0F4.33.0FCNA

Scores by source

Arista (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Arista (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

advisoryarista.com/en/support/advisories-notices/security-advisory/25030-security-advisory-0208