CVE-2026-40969 PUBLISHED

Spring gRPC AuthenticationException message reflected to remote client

Assigner: vmware
Reserved: 16.04.2026 Published: 28.04.2026 Updated: 28.04.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 3.7

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Spring
Product	Spring gRPC
Versions	Default: unaffected affected from 1.0.0 to 1.0.3 (excl.)

References

https://spring.io/security/cve-2026-40969

Problem Types

CWE-209: Generation of Error Message Containing Sensitive Information CWE

Impacts

Unauthenticated callers can read server-side AuthenticationException messages via gRPC status descriptions, leaking information useful for further attacks (CVSS v3.1: low confidentiality impact).