Keycloak lets PAR authorization requests be reused after flow restart
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
Red Hat Build of Keycloak's keycloak-services component mishandles Pushed Authorization Requests (PAR) when an authentication flow is restarted. The restart clears the internal markers that track PAR consumption while the request stays active, so the same authorization request can be reused. A remote attacker with low privileges can use this to obtain multiple access tokens, bypassing the single-use requirement. The flaw is classified as CWE-670.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
A flaw was found in the Pushed Authorization Request PAR implementation of the keycloak-services component. The issue occurs when an authentication flow is restarted, which incorrectly clears the internal markers used to track PAR consumption while leaving the request active. This allows an attacker to reuse the same authorization request to obtain multiple access tokens, bypassing security requirements for single-use requests.
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
Remediation
The sources list no fixed version for Red Hat Build of Keycloak. Red Hat Single Sign-On 7 is not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
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 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Single Sign-On 7
Timeline
- 2026-10-29 Threatist record created from CVE-2026-117859
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-29 Alias added: GHSA-3cf5-cf36-hfwx
- 2026-10-29 CISA SSVC decision points changed
- 2026-10-29 Priority changed: MEDIUM → LOW
References
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Sources
- CVE-2026-117859 · CVE Program
- CVE-2026-117859 · NVD
- FIRST EPSS
- GHSA-3cf5-cf36-hfwx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-117859 · 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