Improper access control in Spring gRPC - CVE-2026-40968
Published: April 28, 2026
Spring gRPC
Detailed vulnerability description
The vulnerability allows a remote user to escalate privileges.
The vulnerability exists due to improper access control in the gRPC worker thread SecurityContext handling when processing a subsequent unauthenticated request after an authorization failure. A remote user can send a request on a reused worker thread to escalate privileges.
The issue occurs when an authenticated identity remains bound to the worker thread after access to a gRPC method is denied.