An authorization bypass was found in the OpenStack Neutron subnetpool onboarding API endpoint (PUT /v2.0/subnetpools/{id}/onboard_network_subnets). When a caller supplies a network_id, the API only verifies that the network is visible to the caller but does not verify that the caller owns the subnets on that network. When a network is RBAC-shared or globally shared, any project member with network visibility can invoke the API to onboard another project's subnets into the caller's own subnetpool, mutating the victim's subnet records (setting subnetpool_id to the attacker-controlled pool). If the attacker's subnetpool is associated with an address scope, Neutron syncs the victim's router interfaces with the attacker-controlled address scope, silently altering L3 routing, NAT, and address-scope behavior. The upstream fix adds an ownership check ensuring the caller has admin-or-owner authority over each subnet being onboarded, not merely visibility of the parent network.

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History

Thu, 30 Jul 2026 02:15:00 +0000

Type Values Removed Values Added
First Time appeared Openstack
Openstack neutron
Vendors & Products Openstack
Openstack neutron

Thu, 30 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Description An authorization bypass was found in the OpenStack Neutron subnetpool onboarding API endpoint (PUT /v2.0/subnetpools/{id}/onboard_network_subnets). When a caller supplies a network_id, the API only verifies that the network is visible to the caller but does not verify that the caller owns the subnets on that network. When a network is RBAC-shared or globally shared, any project member with network visibility can invoke the API to onboard another project's subnets into the caller's own subnetpool, mutating the victim's subnet records (setting subnetpool_id to the attacker-controlled pool). If the attacker's subnetpool is associated with an address scope, Neutron syncs the victim's router interfaces with the attacker-controlled address scope, silently altering L3 routing, NAT, and address-scope behavior. The upstream fix adds an ownership check ensuring the caller has admin-or-owner authority over each subnet being onboarded, not merely visibility of the parent network.
Title openstack-neutron: openstack-neutron: Shared-network consumer can re-scope another project's subnets via subnetpool onboarding
Weaknesses CWE-863
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L'}

threat_severity

Important


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cve-icon MITRE

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cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

Severity : Important

Publid Date: 2026-07-29T15:00:00Z

Links: CVE-2026-55707 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-30T02:00:10Z

Weaknesses