CVE-2026-121291

Security Advisory 0222

Published Nov 10, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed

Description

A crafted Error Report can leave EOS stuck believing that a cache reset is in progress, preventing ROA publication, withdrawal reconciliation, and BGP origin-validation updates.

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
`4.37.0F`	affected	—
`4.36.0F`	affected	≤ 4.36.2F
`4.35.0F`	affected	≤ 4.35.6M

No data.

Vendor Product Versions

Arista

Eos

Version	Status	Scheme	Platform
`4.37.0F`	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']
`[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']

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.413% 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/25044-security-advisory-0222

History

Nov 12, 2026 5:00 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		A crafted Error Report can leave EOS stuck believing that a cache reset is in progress, preventing ROA publication, withdrawal reconciliation, and BGP origin-validation updates.
Title		Security Advisory 0222
Weaknesses		CWE-696
References		https://www.arista.com/en/support/advisories-notices/security-advisory/25044-security-advisory-0222
Metrics		cvssV3_1 `{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}` cvssV4_0 `{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:L/SA:N'}`