CVE-2026-73440

Security Advisory 0178

Published Sep 16, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
On affected platforms running Arista EOS with Simple Network Management Protocol (SNMP) configured, SNMPv3 local or remote user credentials may be exposed as a one-way hashed, localized key value within the device's running and sanitized configurations. An authenticated user who gains access to this sensitive information could leverage it to perform unauthorized read operations on SNMP tables or to send fraudulent trap notifications to the Network Management System (NMS).



This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.

Remediation

Vendor Solution

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Arista recommends customers move to the latest version of each release that contains all the fixes listed below. Following the system upgrade, users are required to execute the syntax conversion command specified below to adopt the updated, encrypted SNMPv3 CLI format: switch# configure convert new-syntax The updated encrypted SNMPv3 CLI configuration follows this structure, incorporating the newly introduced "key <algo> <encrypted_text>" syntax: switch# show running-config | grep snmp-server snmp-server user alice group_alice v3 localized f5717f2cdde9bb946d00 auth sha256 key 7 005D110205085E520B754E1B591C504542585F557D2F217064607A10034752035500080755575640440F5C00505053515F08525208035C1605525E0A040E781F4D CVE-2026-73440 has been fixed in the following releases: * 4.36.3M and later releases in the 4.36.x train * 4.35.7M and later releases in the 4.35.x train * 4.34.9M and later releases in the 4.34.x train * 4.33.11M and later releases in the 4.33.x train


Vendor Workaround

CVE-2026-73440 can be remediated using the hotfix detailed below. This hotfix is strictly applicable to the listed releases. All non-listed versions must be upgraded to a fixed release as specified above.   * 4.36.2F * 4.35.6M * 4.34.8M * 4.33.10M Post hotfix installation, users are required to execute the syntax conversion command to fix the malformed keys. Note: Installing/uninstalling the SWIX will cause the ConfigAgent process to restart. Version: 1.0 URL: SecurityAdvisory178_CVE-2026-73440_Hotfix.swix https://www.arista.com/support/advisories-notices/sa-download/ SWIX hash: 8a11df104d6ada97f0d63ca87a6a03071524038af1f8cd4a0bbcba490ab80245c7b2cfb86be81c5e6773e05801f3df098120f6053b130938230c79193386fe74   For instructions on installation and verification of the hotfix patch, refer to the “ managing eos extensions https://www.arista.com/en/um-eos/eos-managing-eos-extensions ” section in the EOS User Manual. Ensure that the patch is made persistent across reboots by running the command ‘copy installed-extensions boot-extensions’.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description On affected platforms running Arista EOS with Simple Network Management Protocol (SNMP) configured, SNMPv3 local or remote user credentials may be exposed as a one-way hashed, localized key value within the device's running and sanitized configurations. An authenticated user who gains access to this sensitive information could leverage it to perform unauthorized read operations on SNMP tables or to send fraudulent trap notifications to the Network Management System (NMS). This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks. On affected platforms running Arista EOS with Simple Network Management Protocol (SNMP) configured, SNMPv3 local or remote user credentials may be exposed as a one-way hashed, localized key value within the device's running and sanitized configurations. An authenticated user who gains access to this sensitive information could leverage it to perform unauthorized read operations on SNMP tables or to send fraudulent trap notifications to the Network Management System (NMS). This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.
Type Values Removed Values Added
First Time appeared Arista
Arista eos
Vendors & Products Arista
Arista eos
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description On affected platforms running Arista EOS with Simple Network Management Protocol (SNMP) configured, SNMPv3 local or remote user credentials may be exposed as a one-way hashed, localized key value within the device's running and sanitized configurations. An authenticated user who gains access to this sensitive information could leverage it to perform unauthorized read operations on SNMP tables or to send fraudulent trap notifications to the Network Management System (NMS). This issue was discovered internally by Arista, and the company is not aware of any malicious exploitation of this vulnerability in customer networks.
Title Security Advisory 0178
Weaknesses CWE-212
References
Metrics cvssV3_1

{'score': 4.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N'}

cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Arista
Published
Updated
Nov 8, 2026, 10:31 AM
Reserved
Aug 12, 2026, 4:39 PM
Status
Awaiting Analysis
Published
Sep 16, 2026, 10:16 AM
Modified
Nov 8, 2026, 11:16 AM