Auth bypass in OpenStack Cyborg

CVE-2026-40213

OpenStack Cyborg before 16.0.1 uses rule:allow (check_str='@') as the default policy for multiple API endpoints. This unconditionally authorizes any request carrying a valid Keystone token regardless of roles, project membership, or scope. An authenticated user with zero role assignments can complete various actions such as reprogramming FPGA bitstreams on arbitrary compute nodes via agent RPC.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (24.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-40213: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40213?
CVE-2026-40213 is a high-severity vulnerability in OpenStack Cyborg, classified under Incorrect Authorization. CVSS score: 7.4/10. Published 2026-05-07.
How severe is CVE-2026-40213?
High severity. CVSS v3 base score is 7.4 out of 10.