---
id: CVE-2026-9793
title: A flaw was found in Keycloak
summary: >-
  A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted
  request object is submitted, Keycloak may incorrectly process unsigned claims
  if the decrypted content is raw JSON, bypassing the configured signature
  policy. This …
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-347
vendor: redhat
product: build_of_keycloak
affected:
  - build_of_keycloak
published: '2026-05-28'
updated: '2026-08-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-9793'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:50846'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:50847'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:50848'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:50849'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-9793'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2482460'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00256
epssPercentile: 0.15399
ingestedAt: '2026-08-06T05:56:21.614Z'
---

## Overview

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

## Affected

- `build_of_keycloak`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.