CVE-2026-121289

Security Advisory 0208

Published Nov 10, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed

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.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Arista Networks

EOS

unaffected

Version	Status	Constraints
`4.36.0F`	affected	≤ 4.36.2F
`4.35.0F`	affected	≤ 4.35.6M
`4.34.0F`	affected	≤ 4.34.8M
`4.33.0F`	affected	≤ 4.33.10M
`4.25.1F`	affected	< 4.33.0F

No data.

Vendor Product Versions

Arista

Eos

Version	Status	Scheme	Platform
`[4.36.0F,4.36.2F]`	affected	generic	['710_series', '720d_series', '720xp/722xpm_series', '750x_series', '7010tx_series', '7020r/r4_series', '7130_series_running_eos', '7170_series', '7050x3/x4_series', '7060x/x2/x4/x5/x6/xe7_series', '7260x/x3_series', '7280r/r2/r3/r4_series', '7300x/x3_series', '7320x_series', '7358x4_series', '7368x4_series', '7388x5_series', '7500r/r2/r3_series', '7800r3/r4_series', '7700r4_series', 'awe_5000_series', 'awe_7200r_series', 'ztx-7200_series', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange,_virtual_or_physical_appliance']
`[4.35.0F,4.35.6M]`	affected	generic	['710_series', '720d_series', '720xp/722xpm_series', '750x_series', '7010tx_series', '7020r/r4_series', '7130_series_running_eos', '7170_series', '7050x3/x4_series', '7060x/x2/x4/x5/x6/xe7_series', '7260x/x3_series', '7280r/r2/r3/r4_series', '7300x/x3_series', '7320x_series', '7358x4_series', '7368x4_series', '7388x5_series', '7500r/r2/r3_series', '7800r3/r4_series', '7700r4_series', 'awe_5000_series', 'awe_7200r_series', 'ztx-7200_series', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange,_virtual_or_physical_appliance']
`[4.34.0F,4.34.8M]`	affected	generic	['710_series', '720d_series', '720xp/722xpm_series', '750x_series', '7010tx_series', '7020r/r4_series', '7130_series_running_eos', '7170_series', '7050x3/x4_series', '7060x/x2/x4/x5/x6/xe7_series', '7260x/x3_series', '7280r/r2/r3/r4_series', '7300x/x3_series', '7320x_series', '7358x4_series', '7368x4_series', '7388x5_series', '7500r/r2/r3_series', '7800r3/r4_series', '7700r4_series', 'awe_5000_series', 'awe_7200r_series', 'ztx-7200_series', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange,_virtual_or_physical_appliance']
`[4.33.0F,4.33.10M]`	affected	generic	['710_series', '720d_series', '720xp/722xpm_series', '750x_series', '7010tx_series', '7020r/r4_series', '7130_series_running_eos', '7170_series', '7050x3/x4_series', '7060x/x2/x4/x5/x6/xe7_series', '7260x/x3_series', '7280r/r2/r3/r4_series', '7300x/x3_series', '7320x_series', '7358x4_series', '7368x4_series', '7388x5_series', '7500r/r2/r3_series', '7800r3/r4_series', '7700r4_series', 'awe_5000_series', 'awe_7200r_series', 'ztx-7200_series', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange,_virtual_or_physical_appliance']
`[4.25.1F,4.33.0F)`	affected	generic	['710_series', '720d_series', '720xp/722xpm_series', '750x_series', '7010tx_series', '7020r/r4_series', '7130_series_running_eos', '7170_series', '7050x3/x4_series', '7060x/x2/x4/x5/x6/xe7_series', '7260x/x3_series', '7280r/r2/r3/r4_series', '7300x/x3_series', '7320x_series', '7358x4_series', '7368x4_series', '7388x5_series', '7500r/r2/r3_series', '7800r3/r4_series', '7700r4_series', 'awe_5000_series', 'awe_7200r_series', 'ztx-7200_series', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange,_virtual_or_physical_appliance']

Remediation

Vendor Workaround

For BGP sessions that do not rely on the Tunnel Encapsulation Attribute, a workaround is to remove all received Tunnel Encapsulation Attributes by configuring attribute discard, for example: neighbor default received attribute discard 23 Alternatively, a recommended mitigation to reduce exposure to this vulnerability is to configure BGP peer authentication using TCP-AO in order to ensure that only authorized peers can establish a BGP session.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.644% probability within 30 days)

Key SSVC decision points have not yet been added.

References

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

History

Nov 12, 2026 3:30 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Arista Arista eos
Vendors & Products		Arista Arista eos

Nov 10, 2026 8:15 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		Security Advisory 0208
Weaknesses		CWE-121
References		https://www.arista.com/en/support/advisories-notices/security-advisory/25030-security-advisory-0208
Metrics		cvssV3_1 `{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}` cvssV4_0 `{'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'}`