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CVE-2021-4133
A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create…
High8.8EPSS 1.4%
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.
Timeline
ID reserved
By redhat
- 39 days later
· 39 days later
Published
- 3 years later
· 3 years 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 |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (7 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Weakness
Affected products
Keycloak
- affected keycloak 15.1.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-servicesGHSA-83x4-9cwr-5487 (opens in a new tab)
References (4)
- https://bugzilla.redhat.com/show_bug.cgi?id=2033602 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/keycloak/keycloak/issues/9247 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/keycloak/keycloak/security/advisories/GHSA-83x4-9cwr-5487 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.oracle.com/security-alerts/cpuapr2022.html (opens in a new tab)x_refsource_MISCx_transferred
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)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-83x4-9cwr-5487 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-4133)Record last updated .