CVE-2026-51772
Description
A flaw was found in OpenStack Glance. When the multiple locations configuration option is enabled, an authenticated attacker can perform Server-Side Request Forgery (SSRF) by submitting a crafted HTTP request to modify an image's location attributes. This vulnerability allows the attacker to induce the server into making unauthorized network requests to internal or external services, potentially exposing sensitive internal systems.
Statement
This vulnerability is rated as Moderate severity because exploitation requires an authenticated user account and relies on a non-default configuration setting in OpenStack Glance. By default, the show_multiple_locations directive is disabled in Red Hat OpenStack Platform, which prevents standard deployments from being exposed. If enabled, an authenticated user can trigger unauthorized outbound network requests from the Glance service, potentially scanning or probing internal network services.
Mitigation
Disable the multiple locations feature in the Glance configuration.
1. Edit `/etc/glance/glance-api.conf` to set the option to `False` under the `[DEFAULT]` section:
ini
[DEFAULT]
show_multiple_locations = False
2. Restart the Glance API service to apply the change:
bash
systemctl restart openstack-glance-api.service
Caveats:
Disabling `show_multiple_locations` prevents users from viewing or managing alternate image locations, which may affect specific environments or workflows relying on multi-location image storage.
Warning: Restarting the `openstack-glance-api.service` will cause a brief interruption to active Glance API connections and client operations.
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 | 6.5 |
| 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 | High |
| 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:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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