CVE-2026-93856
In OpenStack Cinder through 29.0.0, cross-project information disclosure can occur in the Messages API. A non-admin user with the project-scoped 'member' or 'reader' role making the Block Storage API
OpenStack CinderContainers & cloud
CVSS
4.3MediumExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 21 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.31%Chance of exploitation activity in the next 30 days, higher than 23% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 26.3.1CinderCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
In OpenStack Cinder through 29.0.0, cross-project information disclosure can occur in the Messages API. A non-admin user with the project-scoped 'member' or 'reader' role making the Block Storage API v3.3 "List messages" call finds the non-expired user messages for other projects included in the response, resulting in the leakage of UUIDs of resources owned by other projects, in addition to the user message about the other projects' resources (which, by design, are sanitized generic messages). All Cinder deployments are affected.
Text from CVE List
Affected versions 4
- Cinderaffected: 9.0.0 before 26.3.1CVE List
- Cinderaffected: 27.0.0CVE List
- Cinderaffected: 28.0.0CVE List
- Cinderaffected: 29.0.0CVE List