CVE-2026-18963
Description
A flaw was found in the reset-credentials flow of the keycloak-services component, which is the core engine for identity and access management in Red Hat Build of Keycloak. The issue allows an unauthenticated attacker to force the password reset process for any user without needing to click the required email verification link. This can result in the attacker gaining full control over target user accounts by directly setting new credentials.
Statement
The Red Hat Product Security team has assessed the severity of this vulnerability as Critical, given that it can be exploited by an unauthenticated remote attacker without any user interaction. Successful exploitation allows an attacker to gain full access to any user account by bypassing the email verification step in the password recovery process. The vulnerability's root cause is improper state validation within the reset-credentials authentication flow.
Mitigation
If an immediate upgrade is not possible, disabling the "Forgot password" functionality across all realms can be used as a temporary mitigation.
In the RHBK administration console, navigate to:
Realm settings → Login → Forgot password → Off
Apply this setting to all realms.
Upgrade to a fixed version as soon as possible.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 9.1 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
An attacker could gain unauthorized access to the system by retrieving legitimate user's authentication credentials.
Availability
Technical Impact: DoS: Resource Consumption (Other)
An attacker could deny service to legitimate system users by launching a brute force attack on the password recovery mechanism using user ids of legitimate users.
Integrity,Other
Technical Impact: Other
The system's security functionality is turned against the system by the attacker.
Acknowledgements
Red Hat would like to thank James Paremain for reporting this issue.
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