Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2026-4633 is a low-severity Generation of Error Message Containing Sensitive Information (CWE-209) vulnerability in Redhat Build Of Keycloak. Its CVSS base score is 3.7 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to IA-6 (Authentication Feedback) and SI-11 (Error Handling) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-14400
Vulnerability Data
A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user…
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enumeration.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability enables remote user enumeration via error messages, directly facilitating account discovery (T1087).
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly requires error messages to avoid revealing sensitive information such as user existence, mitigating the CWE-209 differential-error flaw in the identity-first login flow.
Requires obscuring authentication feedback so that login responses do not disclose whether an account exists, directly blocking the enumeration vector.
Enforces uniform access-control decisions and responses during authentication, preventing the system from leaking user-existence information via error paths.
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.
Secure SDLC practices directly require sanitized error handling to prevent sensitive data disclosure.
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.
Secure coding standards explicitly forbid exposing sensitive data in errors.
Security testing can detect error messages that leak sensitive information.
Logging policy can require suppression of sensitive data in error messages.
Secure SDLC mandates error-handling rules that avoid leaking sensitive information.
Application security requirements can specify safe error messaging.
Secure architecture principles include proper exception handling.