---
cve: "CVE-2026-16103"
severity: "MEDIUM"
cvss: 4.3
epss: "0.3%"
vendor: "Generic Security"
kev: false
exploited: false
published: "2026-07-17 17:17:14"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T13:20:09+02:00"
---

# CVE-2026-16103

> 4.3 MEDIUM

## Beschreibung

A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Erforderlich | good |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Keine | good |
| A Verfügbarkeit | Keine | good |

## Referenzen

- <https://access.redhat.com/security/cve/CVE-2026-16103>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2501736>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-16103) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_