# CVE-2026-40969: Spring gRPC AuthenticationException message reflected to remote client

> An attacker can obtain sensitive authentication failure details from gRPC status descriptions, aiding further attacks.

- **Severity:** Low 3.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Apr 2026
- **Updated:** 28 Apr 2026
- **Also known as:** GHSA-37w2-q6vh-45v6

## What is CVE-2026-40969?

CVE-2026-40969 is a low-severity vulnerability in Spring gRPC, published on 28 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The raw message of every server-side AuthenticationException is returned to the unauthenticated remote caller in the gRPC status description. This allows an attacker to obtain information about the authentication failure, which may be useful for further attacks.

Affected versions:
Spring gRPC: 1.0.0 - 1.0.2 (fixed in 1.0.3). Older, unsupported versions are also affected.

Weakness: CWE-209 (Generation of Error Message Containing Sensitive Information)

## Which versions are affected by CVE-2026-40969?

2 open source packages ship an affected version, including org.springframework.grpc:spring-grpc. It affects 1 product.


| Package | Ecosystem | 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: Vmware Spring Grpc.

## How do I fix CVE-2026-40969?

Upgrade org.springframework.grpc:spring-grpc to 1.0.3 or later.

## Is CVE-2026-40969 being exploited?

There is no known exploitation of CVE-2026-40969 in the wild and no public exploit code.

## Other vulnerabilities in Spring gRPC

- [CVE-2026-40968](https://insights.sbomify.com/CVE-2026-40968/): Spring gRPC SecurityContext leaks across requests on authorization failure (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40969 and fix it if it is affected.

What it is: CVE-2026-40969 is a low-severity vulnerability in Spring gRPC, published on 28 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-40969 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.springframework.grpc:spring-grpc (Maven): affected all versions; fixed in 1.0.3
- org.springframework.grpc:spring-grpc (Maven): affected all versions; fixed in 1.0.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-40969/ (Markdown: https://insights.sbomify.com/CVE-2026-40969/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40969
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40969
- OSV: https://osv.dev/vulnerability/CVE-2026-40969

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40969/
Summaries are generated and may contain mistakes; the official description above is the record.