CVE-2026-40969: Spring gRPC AuthenticationException message reflected to remote client
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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-40969?
CVE-2026-40969 has a medium severity rating as it can lead to information disclosure on authentication failures.
How do I fix CVE-2026-40969?
To fix CVE-2026-40969, upgrade to Spring gRPC version 1.0.3 or later to mitigate the exposure of sensitive information.
What kind of information can be exposed due to CVE-2026-40969?
CVE-2026-40969 can expose raw messages of AuthenticationException, potentially revealing details about the authentication failure.
What is the impact of CVE-2026-40969 on my application?
The impact of CVE-2026-40969 is that it can lead to an attacker gaining insights into authentication mechanisms and potential vulnerabilities.
Which versions of Spring gRPC are affected by CVE-2026-40969?
Spring gRPC versions prior to 1.0.3 are affected by CVE-2026-40969 and should be updated to mitigate the vulnerability.