Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NSummary
CVE-2026-33736 is a medium-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Chamilo Chamilo Lms. Its CVSS base score is 6.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 11th 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 AC-6 (Least Privilege) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21567
Vulnerability Data
Chamilo LMS is a learning management system. Prior to 2.0.0-RC.3, any authenticated user (including ROLE_STUDENT) can enumerate all platform users and access personal information (email, phone, roles) via GET /api/users, including administrator accounts. This vulnerability is fixed in 2.0.0-RC.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Directly enables authenticated account enumeration including emails/roles via improper authorization on /api/users endpoint.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authorization policy on API endpoints so that ROLE_STUDENT cannot retrieve the full user list or PII.
Ensures student accounts receive only the minimal privileges required, blocking access to administrative user-enumeration functions.
Controls information flows between subjects so that user-directory data is not released to unauthorized roles via the /api/users path.
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.