CVE-2026-9704
Keycloak: keycloak: privilege escalation due to oversized subject_token jwt
Description
A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.
No summary for this CVE yet.
CVSS Vector Breakdown
Exploitability
AV:NAttack VectorNetwork
AC:HAttack ComplexityHigh
PR:LPrivileges RequiredLow
UI:NUser InteractionNone
Scope
S:UScopeUnchanged
Impact
C:HConfidentialityHigh
I:HIntegrityHigh
A:NAvailabilityNone
Weaknesses
Affected Products
Red Hat
commercial·USaka redhat
Exploitability
Official Patch Available
Workaround Available
References
https://access.redhat.com/errata/RHSA-2026:25097
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:25098
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:30049
access.redhat.com
and 3 more references View all →
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