CVE-2026-1035
Org.keycloak.protocol.oidc: keycloak refresh token reuse bypass via toctou race condition
CVSS Score
3.1
EPSS Score
0.0%
EPSS Percentile
1th
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.
| CWE | CWE-367 |
| Vendor | red hat |
| Product | red hat build of keycloak 26.4 |
| Published | Jan 21, 2026 |
| Last Updated | Apr 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4
All versions affected Red Hat / Red Hat build of Keycloak 26.4.11
All versions affected Red Hat / Red Hat JBoss Enterprise Application Platform 8
All versions affected Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions affected Red Hat / Red Hat Single Sign-On 7
All versions affected References
Credits
Red Hat would like to thank Mohamed Amine ait Ouchebou (mrecho) (Indiesecurity) for reporting this issue.