Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4.12-1 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4-17 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4-17 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4.12 | — | — | Not affected | CNA |
| — | org.keycloak:keycloak-services (Maven) | before 26.6.2 | 26.6.2 | Patch available | GHSA-hq3p-w4xv-x7vp |
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4.12-1 Patch available CNA
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-17 Patch available CNA
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-17 Patch available CNA
- Red Hat build of Keycloak 26.4.12 VendorRed Hat Affected — Fixed in — Not affected CNA
- org.keycloak:keycloak-services (Maven) Vendor— Affected before 26.6.2 Fixed in 26.6.2 Patch available GHSA-hq3p-w4xv-x7vp
Remediation
- Fix · GHSA-hq3p-w4xv-x7vp org.keycloak:keycloak-services (Maven) Fixed in 26.6.2 Advisory →
Red Hat 2 advisories
- RHSA-2026:19597 Released 2026-05-20 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.12 Images Security Update
- Red Hat build of Keycloak 26.4 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:19596 Released 2026-05-20 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.12 Security Update
- Red Hat build of Keycloak 26.4.12
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat build of Keycloak 26.4 | Fixed | RHSA-2026:19597 |
| Red Hat build of Keycloak 26.4.12 | Fixed | RHSA-2026:19596 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-7571
- 2026-10-03 Alias added: GHSA-hq3p-w4xv-x7vp
References
Advisory 5
More Red Hat Build Of Keycloak vulnerabilities
- TI-2026-02223 Keycloak: keycloak: unauthorized authentication via disabled saml identity provider CVSS 3.1HIGH 8.1
- TI-2024-01049 Keycloak: path transversal in redirection validation CVSS 3.1HIGH 8.1
- TI-2026-13740 Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction CVSS 3.1CRITICAL 9.8
- TI-2026-13741 Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation CVSS 3.1CRITICAL 9.1
- TI-2026-13106 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation CVSS 3.1HIGH 8.8
- TI-2026-02631 Authentication bypass in Red Hat build of Keycloak 26.2 CVSS 3.1HIGH 8.8
Sources
- CVE-2026-7571 · CVE Program
- CVE-2026-7571 · NVD
- FIRST EPSS
- GHSA-hq3p-w4xv-x7vp · GitHub Advisory Database · CC BY 4.0
- CVE-2026-7571 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences