Improper input validation in Red Hat build of Keycloak 26.4
Priority LOW 22CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
A flaw was found in the SAML protocol implementation of Keycloak, an open-source identity and access management solution. The issue occurs when Keycloak handles SAML authentication requests using the HTTP-Redirect binding. If a client is configured with a wildcard redirect URL, an attacker can craft a request that includes malicious parameters. When a user authenticates, Keycloak appends its legitimate response to the attacker's parameters. This can cause some service providers to process the attacker's data instead of the real login information, potentially leading to a user being logged into the wrong account.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00523 44th percentileScored 2026-11-07
Fix Fixed Red Hat: 4 advisories
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 | — | 26.4.17-2 | 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 26.6 | — | 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 Data Grid 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | Not affected | CNA |
| Red Hat | Red Hat Single Sign-On 7 | — | — | Not affected | 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 26.6 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 Data Grid 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — Not affected CNA
Remediation
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: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| 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 |
Not affected: 3 products
- Red Hat Data Grid 8
- Red Hat JBoss Enterprise Application Platform Expansion Pack
- Red Hat Single Sign-On 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18217
- 2026-10-03 Alias added: GHSA-82v3-6227-jc8x
- 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
References
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-2026-18217 · CVE Program
- CVE-2026-18217 · NVD
- FIRST EPSS
- GHSA-82v3-6227-jc8x · GitHub Advisory Database · CC BY 4.0
- CVE-2026-18217 · Red Hat security data · CC BY 4.0
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