Auth bypass in OpenStack Neutron

CVE-2026-55707

In OpenStack Neutron before 28.0.2, the subnetpool onboarding API does not verify ownership of the target subnets. An authenticated user can onboard subnets from another project's shared network into their own subnetpool, mutating the victim's subnet state and altering L3 routing and address scope behavior for victim routers.

Vulnerability class: Broken Access Control

EPSS: 0.003 (21.2th percentile) — read the EPSS interpretation.