Cisco Nexus 9000 ACI Mode Switch Software (fabric infrastructure VLAN): TENANT ISOLATION: the earlier instance

CVE-2019-1890Firmware, BMC & network fabriccurated

Impact

TENANT ISOLATION: the earlier instance of the same ACI class of bug — security validation on infrastructure-VLAN connection setup can be bypassed, letting an adjacent device join the fabric's internal VLAN. Worth tracking separately because the fixed releases differ and clusters running older ACI trains are exposed to this one and not the 2021 variant.

Who can reach it

Unauthenticated, adjacent — a device connected to a leaf port.

What to do

ACI fabric software upgrade (APIC + switches). Staged, multi-hour. No config-only workaround beyond locking down unused ports.

References

https://nvd.nist.gov/vuln/detail/CVE-2019-1890

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.