CVE-2026-16103
MEDIUM 4.3 ALL-YEARSA 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 10th percentile
Impact if exploited
4.3CVSS 3.1 · MEDIUM · CNA
- ConfidentialityLow
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ⚠User interaction: A user must take an action (click / open a file)
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
No public exploit or proof-of-concept code is catalogued for this CVE (no ExploitDB, Nuclei, or CISA-KEV entry). It may still exist — search GitHub or check the references below.
Affected
Products Red Hat Build Of Keycloak Red Hat Data Grid 8 Red Hat Jboss Enterprise Application Platform Expansion Pack Red Hat Single Sign On 7 Build Of Keycloak
Weakness (CWE)
- CWE-841: Improper Enforcement of Behavioral Workflow
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Redhat | Build Of Keycloak | * |
All CVSS metrics
- MEDIUM 4.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N - MEDIUM 4.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N