CVE-2026-40968 Spring gRPC SecurityContext leaks across requests on authorization failure
Authenticated identity leaks to subsequent unauthenticated requests on the same thread, allowing privilege escalation in Spring gRPC applications.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40968?
CVE-2026-40968 is a medium-severity authentication bypass vulnerability in Spring gRPC, published on 28 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
When an authenticated user is denied access to a gRPC method, their authenticated identity remains bound to the gRPC worker thread and can be inherited by a subsequent unauthenticated request on the same thread. This may allow the subsequent user to gain escalated permissions.
Affected versions: Spring gRPC: 1.0.0 - 1.0.2 (fixed in 1.0.3). Older, unsupported versions are also affected.
Weakness: CWE-653
Which versions are affected by CVE-2026-40968?
2 open source packages ship an affected version, including org.springframework.grpc:spring-grpc. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.springframework.grpc:spring-grpc Maven | All versions | 1.0.3 |
org.springframework.grpc:spring-grpc Maven | All versions | 1.0.3 |
Products include Vmware Spring Grpc.
How do I fix CVE-2026-40968?
Upgrade org.springframework.grpc:spring-grpc to 1.0.3 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-40968 being exploited?
There is no known exploitation of CVE-2026-40968 in the wild and no public exploit code.
Other vulnerabilities in Spring gRPC
Sources
Also known as GHSA-4g9c-3x4p-mfpp.