Arista EOS: SNMPv3 localized key hashes exposed in running and sanitized configurations

CVSS 2.3CVE-2026-73440Firmware, BMC & network fabriccurated

Impact

On Arista EOS switches with SNMP configured, SNMPv3 user credentials can show up as hashed, localized key values in both the running configuration and the sanitized one. The sanitized config is the copy that often goes into support bundles and config backups. An authenticated user who obtains that value can read SNMP tables without authorisation or send fraudulent traps to the NMS. That can leak fabric topology and counters, or inject false alerts into fabric monitoring. Arista found the issue internally and knows of no exploitation.

Who can reach it

An authenticated user who can view the switch configuration, or anyone who has a sanitized config export. Using the key then requires SNMP reachability to the switch or to the NMS.

What to do

Follow Arista Security Advisory 0178 for the fixed EOS releases and any workaround. The record does not list versions. Treat configs and support bundles that have already been exported as containing SNMPv3 key material, and consider rotating SNMPv3 credentials after upgrading.

References

https://nvd.nist.gov/vuln/detail/CVE-2026-73440 https://www.arista.com/en/support/advisories-notices/security-advisory/24734-security-advisory-0178

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.