CVE-2026-103112
Description
A flaw was found in the authentication session handling of the keycloak-services component in Keycloak. The issue occurs because the system fails to verify if an authenticator is valid for the current authentication flow when switching between the standard authentication path and the reset credentials path. An authenticated attacker can exploit this by triggering a race condition during the credential reset process to associate their successful authentication state with another user's session. This can result in the attacker gaining full access to the victim's account and changing their password.
Statement
The Red Hat Product Security team has assessed the severity of this vulnerability as Important, given that exploitation requires a difficult-to-achieve race condition and specific realm configurations. Successful exploitation allows an attacker to perform a full account takeover, including changing the victim's password and accessing their data. The vulnerability's root cause is a failure to verify that an authenticator is appropriate for the active authentication flow, combined with insecure handling of concurrent session updates.
Mitigation
--- CME Mitigation Guidance (2026-11-06) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to validate that the requested authenticator ID belongs to the active execution flow when switching between authenticate and reset-credentials endpoints in keycloak-services: upgrade to Red Hat build of Keycloak 26.4.17, 26.6.8 (or the fixed Rhbk/Keycloak Rhel/Keycloak Services builds), which validate that the requested authenticator ID is present in the active execution flow when switching between authenticate and reset-credentials endpoints, closing concurrent race condition between reset-credentials and authenticate endpoints during flow switching. Until patched, this is a concern on Keycloak deployments with Forgot Credentials enabled and users without two-factor authentication, so Enforce two-factor authentication for all realm users or disable the Forgot Credentials feature to prevent cross-flow identity binding. These controls limit blast radius and contain exploitation, but they do not fix the underlying authentication race condition defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-801 Multi-Factor Authentication (MFA) (high)
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability
When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.
Confidentiality,Integrity
Technical Impact: Read Files or Directories; Read Application Data
When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).
Access Control
Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism
This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
Frequently Asked Questions
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