CVE-2026-9704
MEDIUM
6,8
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: low
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: none
Description
AI Translation Available
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.
1284
Improper Validation of Specified Quantity in Input
IncompleteCommon Consequences
Security Scopes Affected:
Other
Integrity
Availability
Potential Impacts:
Varies By Context
Dos: Resource Consumption (Cpu)
Modify Memory
Read Memory
Applicable Platforms
All platforms may be affected
https://access.redhat.com/security/cve/CVE-2026-9704
https://bugzilla.redhat.com/show_bug.cgi?id=2481877