Keycloak SAML broker skips proof of key possession for assertions
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 4 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-287.
Summary
Red Hat build of Keycloak 26.4 and 26.6 and Red Hat Single Sign-On 7 are affected. The SAML identity broker does not verify that a user holds the private key tied to a holder-of-key assertion, which is CWE-287 improper authentication. A remote attacker who intercepts a victim's signed assertion can replay it to impersonate the victim without the victim's private key, though the attack is hard to carry out.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
A flaw was found in the SAML identity broker component of Keycloak, which is used to delegate authentication to external identity providers. The issue occurs because the broker fails to verify that a user actually possesses the private key associated with a holder-of-key assertion. An attacker who intercepts a victim signed assertion can replay it to gain unauthorized access and impersonate the victim without needing their private key.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4.17-2 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4-29 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4 | — | 26.4-30 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.4.17 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.4.17 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.4.17 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6.8-2 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-24 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-24 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Single Sign-On 7 | — | — | No fix listed | CNA |
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4.17-2 Patch available CNA
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-29 Patch available CNA
- Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-30 Patch available CNA
- Red Hat build of Keycloak 26.4.17 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.4.17 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.4.17 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6.8-2 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-24 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-24 Patch available CNA
- Red Hat build of Keycloak 26.6.8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6.8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6.8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
Remediation
Upgrade Red Hat build of Keycloak 26.4 to 26.4-29, 26.4-30 or 26.4.17-2, and 26.6 to 26.6-24 or 26.6.8-2. The fixes are listed in RHSA-2026:95759, RHSA-2026:95760, RHSA-2026:95761 and RHSA-2026:95762. The sources list no fixed version for Red Hat Single Sign-On 7, and Red Hat's plan for it is none available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Red Hat 4 advisories
- RHSA-2026:95762 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Images Security Update
- Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:95760 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.17 Images Security Update
- Red Hat build of Keycloak 26.4 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:95761 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Security Update
- Red Hat build of Keycloak 26.6.8
Show 1 more Red Hat advisories
- RHSA-2026:95759 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.4.17 Security Update
- Red Hat build of Keycloak 26.4.17
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Single Sign-On 7 | Affected | No fix yet: Fix deferred |
| Red Hat build of Keycloak 26.4 | Fixed | RHSA-2026:95760 |
| Red Hat build of Keycloak 26.4.17 | Fixed | RHSA-2026:95759 |
| Red Hat build of Keycloak 26.6 | Fixed | RHSA-2026:95762 |
| Red Hat build of Keycloak 26.6.8 | Fixed | RHSA-2026:95761 |
Timeline
- 2026-11-05 Threatist record created from CVE-2026-92855
- 2026-11-05 Alias added: GHSA-486h-gxch-8c4x
- 2026-11-05 Affected versions changed · Red Hat
- 2026-11-05 CVSS score added · Red Hat
- 2026-11-06 Fix available: [email protected], [email protected], [email protected] · CNA
- 2026-11-06 2 new references · CNA
- 2026-11-06 Fix available: RHSA-2026:95761 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.6.8 · Red Hat
- 2026-11-06 Fix available: rhbk/[email protected], rhbk/[email protected], rhbk/[email protected] +3 · CNA
- 2026-11-06 2 new references · CNA
- 2026-11-06 Fix available: RHSA-2026:95760 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95762 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95759 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.17, Red Hat build of Keycloak 26.6 · Red Hat
- 2026-11-07 Priority changed: MEDIUM → LOW
References
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Sources
- CVE-2026-92855 · CVE Program
- CVE-2026-92855 · NVD
- FIRST EPSS
- GHSA-486h-gxch-8c4x · GitHub Advisory Database · CC BY 4.0
- CVE-2026-92855 · 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