CVE-2026-19655

Published Sep 15, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

Description

On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.

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
`4.35.0`	affected	≤ 4.35.5M
`4.34.0`	affected	≤ 4.34.7.1M
`4.33.0`	affected	≤ 4.33.9M

No data.

Vendor Product Versions

Arista

Eos

Version	Status	Scheme	Platform
`[4.35.0,4.35.5M]`	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_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', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange', 'virtual_or_physical_appliance']
`[4.34.0,4.34.7.1M]`	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_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', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange', 'virtual_or_physical_appliance']
`[4.33.0,4.33.9M]`	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_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', 'cloudeos', 'ceos-lab', 'veos-lab', 'cloudvision_exchange', 'virtual_or_physical_appliance']

Remediation

Vendor Solution

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. CVE-2026-19655 has been fixed in the following releases: * 4.35.6M and later releases in the 4.35.x train * 4.34.8M and later releases in the 4.34.x train * 4.33.10M and later releases in the 4.33.x train

Vendor Workaround

There is no workaround known for this issue.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

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% (0.303% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://www.arista.com/en/support/advisories-notices/security-advisory/24711-security-advisory-0155

History

Nov 10, 2026 11:00 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

Sep 16, 2026 7:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 15, 2026 9:15 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 Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthenticated attacker connected to a client-facing VLAN(s) where the relay is configured can send a specially crafted packet that causes the DHCP Relay service to restart.
Title		On affected platforms running Arista EOS with Dynamic Host Configuration Protocol (DHCP) relay/snooping configured with the information option (Option 82), or with the DHCP server configured with match criteria based on the information option, an unauthent
Weaknesses		CWE-20
References		https://www.arista.com/en/support/advisories-notices/security-advisory/24711-security-advisory-0155
Metrics		cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}` cvssV4_0 `{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`