CVE-2026-109082
MEDIUM 6.8A flaw was found in the Client-Initiated Backchannel Authentication CIBA implementation within the keycloak-services component of Keycloak. This component handles advanced authentication flows where a client initiates a login on behalf of a user. The issue occurs because Keycloak fails to verify that a client is authorized to use the CIBA flow, allowing public clients to bypass security requirements. An attacker could use this flaw to trick a user into approving a login request, eventually gaining full access to the users account without needing a client secret.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 15th percentile
Impact if exploited
6.8CVSS 3.1 · MEDIUM
- ConfidentialityHigh
- IntegrityHigh
- 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: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-109082/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-109082/poc.json
Weakness (CWE)
- CWE-287: Improper Authentication
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
All CVSS metrics
- MEDIUM 6.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - MEDIUM 6.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N