CVE-2026-50266: OpenStack Neutron Neutron Port RBAC Policy Bypass Vulnerability

LOW
Advisory Identifier: GHSA-qmc5-gv6v-8p22
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CVSS 2.2
CWE-863
Published
Advisory Summary

CVE-2026-50266 is a LOW (CVSS 2.2) neutron port rbac policy bypass vulnerability (CWE-863: Incorrect Authorization) affecting OpenStack Neutron libraries in the PyPI ecosystem. The issue involves neutron port rbac policy bypass allows project managers to set trusted device owners on shared networks. Remediation is available by upgrading affected packages to version 28.0.1.

CVE-2026-50266 at a Glance

CVE Identifier CVE-2026-50266
GHSA Identifier GHSA-qmc5-gv6v-8p22
Severity LOW
CVSS v3.1 Base Score 2.2
CWE Classification CWE-863: Incorrect Authorization
Affected Product OpenStack Neutron
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 2.2

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-50266

To remediate this vulnerability, upgrade all affected OpenStack Neutron dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

neutron fixed: 28.0.1 
pip install neutron>=28.0.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show neutron

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-50266, inspect your installed packages using pip:

pip show neutron

Analyze the terminal output to locate any version of OpenStack Neutron in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 28.0.1), your application is affected.

Note: The pip show neutron command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In OpenStack Neutron, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In OpenStack Neutron before 28.0.1, a project manager can create or update a port on a shared network owned by another project and set device_owner to a value that has "network:" at the beginning ("network:dhcp" for example). The default port RBAC policies incorrectly included PROJECT_MANAGER without requiring network ownership, allowing any project manager to obtain trusted network-service port behavior on shared networks. Depending on backend and deployment, this can bypass anti-spoofing and security group protections, enabling DHCP, MAC, or IP spoofing against other tenants on the shared network. This is a regression of CVE-2015-5240 (OSSA-2015-018).

CVE-2026-50266 Affected OpenStack Neutron Versions

1 component(s)
Fixed Versions:
28.0.1
Product / Package Ecosystem Affected Versions Fixed Version
neutron
pypi/neutron
PyPI
< 28.0.1
28.0.1

References

NVD — CVE-2026-50266 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-50266
bugs.launchpad.net/neutron/+bug/215211... WEB
https://bugs.launchpad.net/neutron/+bug/2152115
OpenStack Neutron Source Repository REPOSITORY
https://github.com/openstack/neutron
launchpad.net/bugs/2152115 WEB
https://launchpad.net/bugs/2152115
review.opendev.org/990273 WEB
https://review.opendev.org/990273
review.opendev.org/990353 WEB
https://review.opendev.org/990353
review.opendev.org/990356 WEB
https://review.opendev.org/990356
OpenStack Neutron Security Information SECURITY
https://www.openwall.com/lists/oss-security/2026/06/04/6

Frequently Asked Questions

What is CVE-2026-50266?
CVE-2026-50266 is a security vulnerability in OpenStack Neutron involving Neutron port RBAC policy bypass allows project managers to set trusted device owners on shared networks under CWE-863: Incorrect Authorization.
Which OpenStack Neutron versions are affected?
Affected versions include releases prior to 28.0.1 across affected packages: neutron.
What version fixes CVE-2026-50266?
Upgrading to 28.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is neutron affected?
Yes, neutron is affected in releases prior to 28.0.1. Upgrade your dependency to 28.0.1 or later.
What is the CVSS score of CVE-2026-50266?
CVE-2026-50266 has a CVSS v3.1 base score of 2.2 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2026-50266?
CVE-2026-50266 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check PyPI dependencies for CVE-2026-50266?
Run the dependency tree command: 'pip show neutron'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qmc5-gv6v-8p22",
  "modified" : "2026-07-15T22:40:05Z",
  "published" : "2026-06-04T18:30:32Z",
  "aliases" : [ "CVE-2026-50266" ],
  "summary" : "OpenStack Neutron: Neutron port RBAC policy bypass allows project managers to set trusted device owners on shared networks",
  "details" : "In OpenStack Neutron before 28.0.1, a project manager can create or update a port on a shared network owned by another project and set device_owner to a value that has \"network:\" at the beginning (\"network:dhcp\" for example). The default port RBAC policies incorrectly included PROJECT_MANAGER without requiring network ownership, allowing any project manager to obtain trusted network-service port behavior on shared networks. Depending on backend and deployment, this can bypass anti-spoofing and security group protections, enabling DHCP, MAC, or IP spoofing against other tenants on the shared network. This is a regression of CVE-2015-5240 (OSSA-2015-018).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "neutron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "28.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-50266"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.launchpad.net/neutron/+bug/2152115"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openstack/neutron"
  }, {
    "type" : "WEB",
    "url" : "https://launchpad.net/bugs/2152115"
  }, {
    "type" : "WEB",
    "url" : "https://review.opendev.org/990273"
  }, {
    "type" : "WEB",
    "url" : "https://review.opendev.org/990353"
  }, {
    "type" : "WEB",
    "url" : "https://review.opendev.org/990356"
  }, {
    "type" : "WEB",
    "url" : "https://www.openwall.com/lists/oss-security/2026/06/04/6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-15T22:40:05Z",
    "nvd_published_at" : "2026-06-04T17:16:33Z"
  }
}