Keycloak-services: keycloak-services: saml onetimeuse assertion replay in idp-initiated broker flow
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-294.
Summary
A flaw was found in the SAML broker component of Keycloak, an identity and access management solution. When configured as a SAML broker using the IdP-Initiated flow, Keycloak fails to enforce the OneTimeUse condition in SAML assertions. This allows an attacker who captures a valid, unused assertion to replay it multiple times. Successful exploitation could allow an attacker to hijack a user's session and gain unauthorized access to the system as that user.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
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 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Build of Keycloak | — | — | No fix listed | CNA |
| Red Hat | Red Hat Build of Keycloak | — | — | No fix listed | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | No fix listed | CNA |
| Red Hat | Red Hat Single Sign-On 7 | — | — | Not affected | CNA |
- Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Build of Keycloak VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — Not affected CNA
Remediation
No fixed version listed by the sources yet.
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 |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Single Sign-On 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18967
- 2026-10-03 Alias added: GHSA-fghp-hcwh-75j2
References
Other 1
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-2026-18967 · CVE Program
- CVE-2026-18967 · NVD
- FIRST EPSS
- GHSA-fghp-hcwh-75j2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-18967 · 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