Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2026-5138 is a medium-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 4.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique System Network Configuration Discovery (T1016); ranked at the 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-41004
Vulnerability Data
A flaw was found in Foreman. An authenticated user with host-edit permissions could exploit a cross-tenant information disclosure vulnerability. This flaw occurs because the taxonomy_scope controller method does not properly validate organization and location IDs from nested request parameters, bypassing…
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existing authorization checks. This allows the user to leak sensitive infrastructure metadata, including subnet topology, IP ranges, gateways, DNS servers, and VLAN IDs, from organizations and locations they are not authorized to access.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Directly enables unauthorized System Network Configuration Discovery (subnet topology, IP ranges, gateways, DNS, VLANs) via authz bypass.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authorization decisions on host and taxonomy resources so that manipulated organization/location IDs cannot bypass access checks.
Requires validation of all organization and location identifiers supplied in nested request parameters before they are used to scope queries.
Enforces information-flow rules between separate organization/location security domains, blocking unauthorized leakage of subnet, IP, and VLAN metadata.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing authorization checks but does not prevent the weakness in production.
Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.