High severity · published Sep 17, 2026
CVE-2026-90997
Keycloak-services: keycloak: replay protection bypass leads to unauthorized access via database driver semantics mismatch
7.4
CVSS
0.4%
EPSS
No
On KEV
Description
A flaw was found in Keycloak. When deployed in stateless mode with MySQL or MariaDB, a mismatch in row-count semantics between the database driver and Keycloak's application logic allows an attacker to bypass replay protection. This vulnerability enables an attacker who intercepts single-use security artifacts, such as JWT client assertions, DPoP proofs, or one-time password (TOTP) codes, to replay them. Successful exploitation grants unauthorized access to the token endpoint or login flow.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Keycloak · Keycloak
26.7.0 before 26.7.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-90997
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-90997
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-90997
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2533141
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