Resource allocation without limits in Red Hat build of Keycloak 26.6
Priority LOW 30CWE-770Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-770.
Summary
A flaw was found in the user-event metrics recording of Keycloak. When metrics are enabled, the system records raw error messages from failed account operations as Prometheus metric labels. Because these error messages can include user-supplied input like nonexistent client IDs, an authenticated user can create a massive number of unique metric entries, eventually exhausting system memory and causing the service to crash or become unavailable.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00552 46th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 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 26.6 | — | 26.6.5-1 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-11 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6 | — | 26.6-11 | Patch available | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.5 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.5 | — | — | Not affected | CNA |
| Red Hat | Red Hat build of Keycloak 26.6.5 | — | — | 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 26.6 VendorRed Hat Affected — Fixed in 26.6.5-1 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-11 Patch available CNA
- Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-11 Patch available CNA
- Red Hat build of Keycloak 26.6.5 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6.5 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat build of Keycloak 26.6.5 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 2 advisories
- RHSA-2026:50849 Released 2026-08-05 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.5 Images Security Update
- Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:50848 Released 2026-08-05 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.5 Security Update
- Red Hat build of Keycloak 26.6.5
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 26.6 | Fixed | RHSA-2026:50849 |
| Red Hat build of Keycloak 26.6.5 | Fixed | RHSA-2026:50848 |
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-2026-16100
- 2026-10-03 Alias added: GHSA-xj3w-m54w-h7p9
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-2026-16100 · CVE Program
- CVE-2026-16100 · NVD
- FIRST EPSS
- GHSA-xj3w-m54w-h7p9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-16100 · 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