CVE-2026-50266: Auth Bypass (CVSS 2.2)

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).

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CVSS v3.1 Score

2.2

LOW

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0026

Probability of exploitation

0.18%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

References

Other 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 https://bugs.launchpad.net/neutron/+bug/2152115

Frequently Asked Questions

What is 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 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). It has a CVSS v3.1 base score of 2.2 (LOW).

How severe is CVE-2026-50266? +

CVE-2026-50266 has a CVSS v3.1 score of 2.2 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-50266? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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