Infinite loop in Red Hat keycloak
Priority LOW 36CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-835.
Summary
It was found that when Keycloak before 2.5.5 receives a Logout request with a Extensions in the middle of the request, the SAMLSloRequestParser.parse() method ends in a infinite loop. An attacker could use this flaw to conduct denial of service attacks.
Why it matters now
EPSS 0.0183 78th percentileScored 2026-11-07
Fix Fixed org.keycloak:keycloak-core (Maven): 2.5.5
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 | keycloak | 2.5.5 | — | No fix listed | CNA |
| — | org.keycloak:keycloak-core (Maven) | before 2.5.5 | 2.5.5 | Patch available | GHSA-jc6q-27mw-p55w |
- keycloak VendorRed Hat Affected 2.5.5 Fixed in — No fix listed CNA
- org.keycloak:keycloak-core (Maven) Vendor— Affected before 2.5.5 Fixed in 2.5.5 Patch available GHSA-jc6q-27mw-p55w
Remediation
- Fix · GHSA-jc6q-27mw-p55w org.keycloak:keycloak-core (Maven) Fixed in 2.5.5 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 1 product
- Red Hat Single Sign-On 7
Timeline
- 2026-10-02 Threatist record created from CVE-2017-2646
- 2026-10-03 Alias added: GHSA-jc6q-27mw-p55w
References
More Red Hat Keycloak vulnerabilities
- TI-2024-01049 Keycloak: path transversal in redirection validation CVSS 3.1HIGH 8.1
- TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
- TI-2020-08665 Server-side request forgery in keycloak CVSS 3.1MEDIUM 5.3
- TI-2022-03468 Path traversal in Red Hat Keycloak CVSS 3.1CRITICAL 9.1
- TI-2021-03612 A POST based reflected Cross Site Scripting vulnerability on has been identified in Keycloak. CVSS 3.1MEDIUM 6.1
- TI-2022-03994 Cross-site scripting in keycloak CVSS 3.1CRITICAL 10.0
Sources
- CVE-2017-2646 · CVE Program
- CVE-2017-2646 · NVD
- FIRST EPSS
- GHSA-jc6q-27mw-p55w · GitHub Advisory Database · CC BY 4.0
- CVE-2017-2646 · Red Hat security data · CC BY 4.0
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