CVE-2026-92857
Keycloak-services: keycloak-services: dcr protocol mapper config not validated, allowing iat holders to forge sub and aud claims in signed tokens
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.1
Keycloak-services: keycloak-services: dcr protocol mapper config not validated, allowing iat holders to forge sub and aud claims in signed tokens
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.
- Record
CVE-2026-92857- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-20
- Updated
- 2026-11-06
EUVDEUVD-2026-117607
8.1
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.
- Record
EUVD-2026-117607- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-06
GitHub AdvisoriesGHSA-xw5c-j6m6-2hxj
8.1
Keycloak provides a Dynamic Client Registration feature that allows users with specific tokens to...
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.
- Record
GHSA-xw5c-j6m6-2hxj- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-20
- Updated
- 2026-11-06
NVD
8.1
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.
- Record
CVE-2026-92857- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-20
- Updated
- 2026-11-06
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| products, references | CVE List | |
| products, references | EUVD, GitHub Advisories, NVD | |
| products, references | CVE List | |
| products, references | EUVD, NVD | |
| aliases, references | GitHub Advisories | |
| cwes, products, references, severity, title | CVE List | |
| first indexed | EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-92857 is a high vulnerability (CVSS 8.1) in Red Hat Build Of Keycloak 26.4, published November 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 30th percentile. No source names a fixed version.
References
access.redhat.com/errata/RHSA-2026:95759
access.redhat.com/errata/RHSA-2026:95760
access.redhat.com/errata/RHSA-2026:95761
access.redhat.com/errata/RHSA-2026:95762
access.redhat.com/security/cve/CVE-2026-92857
bugzilla.redhat.com/show_bug.cgi?id=2535817
nvd.nist.gov/vuln/detail/CVE-2026-92857
github.com/advisories/GHSA-xw5c-j6m6-2hxj