CVE Vulnerabilities

CVE-2026-4633

Generation of Error Message Containing Sensitive Information

Published: Mar 23, 2026 | Modified: Apr 01, 2026
CVSS 3.x
3.7
LOW
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
3.7 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Ubuntu
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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 enumeration.

Weakness

The product generates an error message that includes sensitive information about its environment, users, or associated data.

Affected Software

NameVendorStart VersionEnd Version
Build_of_keycloakRedhat- (including)- (including)

Potential Mitigations

  • Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
  • If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
  • Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

References