Description
A flaw was found in the Keycloak server during refresh token processing, specifically in the TokenManager class responsible for enforcing refresh token reuse policies. When strict refresh token rotation is enabled, the validation and update of refresh token usage are not performed atomically. This allows concurrent refresh requests to bypass single-use enforcement and issue multiple access tokens from the same refresh token. As a result, Keycloak’s refresh token rotation hardening can be undermined.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.11 | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-keycloak | No fix yet | — |
| Ubuntu 25.10 | python-keycloak | No fix yet | — |
| Ubuntu 24.04 LTS | python-keycloak | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-services | <= 26.2.5 | — | GHSA-m2w5-7xhv-w6fh |
Advisories 1
- WID-SEC-2026-0197 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 6, 2026
References
- RHSA-2026:6477 vendor-advisory
- RHSA-2026:6478 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-1035 vdb-entry
- RHBZ#2430314 issue-tracking