CVE-2026-1035Org.keycloak.protocol.oidc: keycloak refresh token reuse bypass via toctou race condition
- 3.1LowCVSS base score
- 0.30%Exploitation in 30 daysEPSS · top 77% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By redhat
- 5 days later
· 5 days later
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Low3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Deferred | 3.1 | Low3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.30% · top 77% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.1.
Affected products
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4.11-1 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-14 – < *
Red Hat · Red Hat build of Keycloak 26.4
- unaffected 26.4-14 – < *
Red Hat · Red Hat build of Keycloak 26.4.11
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform 8
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions: unaffected
Red Hat · Red Hat Single Sign-On 7
All versions: unaffected
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-servicesGHSA-m2w5-7xhv-w6fh (opens in a new tab)
What to do
Workaround: To mitigate this issue, configure the `refreshTokenMaxReuse` policy in Keycloak to a value greater than zero. This prevents the race condition by allowing a limited number of reuses for refresh tokens, thereby maintaining the integrity of the Refresh Token Rotation hardening measure. Consult Keycloak documentation for specific configuration instructions. Changes to Keycloak configuration typically require a service restart or redeployment to take effect.
References
References4
- RHSA-2026:6477 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:6478 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-1035 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2430314 (opens in a new tab)issue-trackingx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-3691 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-m2w5-7xhv-w6fh (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-1035)Record last updated .