Answer in brief
CVE-2026-11800 records a High severity (CVSS 8.1) vulnerability in Org.keycloak:keycloak-services: keycloak: authentication bypass via jwt algorithm confusion. The current sources do not mark it as known exploited. The current feed maps Red Hat/rhbk/keycloak-rhel9 (generic), org.keycloak:keycloak-services (maven), org.keycloak:keycloak-services (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Red Hat/rhbk/keycloak-rhel9 (generic), org.keycloak:keycloak-services (maven), org.keycloak:keycloak-services (maven). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Red Hat/rhbk/keycloak-rhel9generic | * | Not reported |
| org.keycloak:keycloak-servicesmaven | <26.6.4 | 26.6.4 |
| org.keycloak:keycloak-servicesmaven | >=0 <26.6.4 | 26.6.4 |
Published upstream
Jun 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.
Quoted source text, attributed separately from HOL analysis.