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Vulnerability · Published Nov 5, 2026 · Assigned by redhat

CVE-2026-92857Keycloak-services: keycloak-services: dcr protocol mapper config not validated, allowing iat holders to forge sub and aud claims in signed tokens

High 8.1

In plain English

A high-severity improper input validation in Red Hat Build of Keycloak from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.3%top 78.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

Keycloak provides a Dynamic Client Registration feature that allows users with specific tokens to register their own applications. A flaw in how Keycloak validates these registration requests allows an attacker to create a malicious application that forges identity information. By mapping their own user profile details to protected fields like the user ID (sub) or intended audience (aud), an attacker can generate signed security tokens that make them appear to be a different user. This could allow an attacker to impersonate other users or gain unauthorized access to services that rely on these tokens for identity verification.

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Build of Keycloak see references
Red Hat Red Hat Build of Keycloak see references
Red Hat Red Hat Build of Keycloak see references
Red Hat Red Hat Single Sign-On 7 see references

Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References