Improper access control in Spring gRPC - CVE-2026-40968
Published: April 28, 2026
Vulnerability identifier: #VU128369
CSH Severity: Low
CVSS v4: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-40968
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Spring gRPC
How to mitigate CVE-2026-40968
Install security update from vendor's website.
Spring gRPC - update to 1.0.3