Authentication Bypass in Keycloak (CVE-2026-105305)
Summary
Authentication bypass in Keycloak (CVE-2026-105305). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A flaw was found in the OIDC implementation of Keycloak, specifically within the Device Authorization Grant flow. This component allows devices with limited input capabilities to obtain security tokens. The issue occurs because the flow fails to check the minimum authentication level required by a client configuration. This allows an attacker who has stolen a user's password to bypass mandatory multi-factor authentication and gain unauthorized access to the Keycloak Admin REST API.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-105305 has been found in Keycloak.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Keycloak CVE-2026-105305" on the vendor's site.
CVE-2026-105305 (Keycloak) — CWE-287 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in Keycloak.
Check the vendor advisory for the affected versions of Keycloak.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Keycloak' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Keycloak' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Keycloakを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web secalert@redhat.com
- web secalert@redhat.com
- web nvd.nist.gov
- web github.com