CVE-2026-93856
Description
A flaw was found in OpenStack Cinder. An authenticated user with project-level access can retrieve messages intended for other projects by issuing a message listing request to the Block Storage API. This flaw leads to information disclosure, exposing resource identifiers and status messages belonging to other tenants.
Statement
This vulnerability is rated as having Moderate impact by Red Hat because an authenticated user with project-level access can list Cinder user messages that belong to other projects. The response contains predefined, sanitized error text and resource identifiers. It does not include the owning project ID, so the caller cannot tell which project a resource identifier belongs to. Cinder records these messages for errors, not for successful operations. The issue does not expose volume contents and does not allow modification or deletion of other tenants' resources.
Mitigation
Operators can shorten how long these messages remain available by lowering the Cinder message_ttl option. The default is 2592000 seconds (30 days). A periodic task removes expired messages. That task runs on the message_reap_interval, which defaults to 86400 seconds (24 hours). This reduces the window during which another project's error messages can be listed. It does not prevent the list API from returning messages that have not yet expired.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.3 | N/A | 4.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Files or Directories; Read Memory; Read Application Data
Sensitive data may be exposed to attackers.
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