6.8
Medium
CVE-2026-97174 Keycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens
Description
A flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.
CVSS 3.1 detail
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NExploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Build of Keycloak | Versions not published | |
| Red Hat Single Sign-On 7 | Versions not published | |
| Red Hat build of Keycloak 26.6.8 | Versions not published | |
| Red Hat build of Keycloak 26.6 26.6 | earliest → < 26.6-24 | 26.6-24 |
Other CVEs of Red Hat Build of Keycloak
The 277 CVEs of Red Hat Build of Keycloak →
CVE-2026-120984
Keycloak-services: keycloak-services: manage-clients to arbitrary code execution through inline javascript policy import
9.1
Critical
CVE-2026-9797
Keycloak: keycloak: privilege escalation via client authentication manipulation by an authenticated administrator
6.5
Medium
CVE-2026-97848
Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization
6.5
Medium
CVE-2026-97367
Keycloak-services: keycloak-services: dcr azp and sid claim substitution allows account rest session takeover
6.4
Medium