CVE-2026-41081: Apache Storm Client: Anonymous principal assigned on TLS client certificate verification failure
Improper Handling of TLS Client Authentication Failure Leading to Anonymous Principal Assignment in Apache Storm
Versions Affected: up to 2.8.7
Description: When TLS transport is enabled in Apache Storm without requiring client certificate authentication (the default configuration), the TlsTransportPlugin assigns a fallback principal (CN=ANONYMOUS) if no client certificate is presented or if certificate verification fails. The underlying SSLPeerUnverifiedException is caught and suppressed rather than rejecting the connection.
This fail-open behavior means an unauthenticated client can establish a TLS connection and receive a valid principal identity. If the configured authorizer (e.g., SimpleACLAuthorizer) does not explicitly deny access to CN=ANONYMOUS, this may result in unauthorized access to Storm services. The condition is logged at debug level only, reducing visibility in production.
Impact: Unauthenticated clients may be assigned a principal identity, potentially bypassing authorization in permissive or misconfigured environments.
Mitigation: Users should upgrade to 2.8.7 in which TLS authentication failures are handled in a fail-closed manner.
Users who cannot upgrade immediately should: - Enable mandatory client certificate authentication (nimbus.thrift.tls.client.auth.required: true) - Ensure authorization rules explicitly deny access to CN=ANONYMOUS - Review all ACL configurations for implicit default-allow behavior
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-41081?
CVE-2026-41081 has a severity rating that may vary, but it is considered significant due to improper TLS client authentication handling.
How do I fix CVE-2026-41081?
To fix CVE-2026-41081, upgrade Apache Storm to version 2.8.8 or later where the vulnerability is patched.
What versions of Apache Storm are affected by CVE-2026-41081?
CVE-2026-41081 affects Apache Storm versions up to and including 2.8.7.
What causes the vulnerability in CVE-2026-41081?
The vulnerability in CVE-2026-41081 is caused by improper handling of TLS client authentication failure, leading to the assignment of an anonymous principal.
Is there a workaround for CVE-2026-41081 if I cannot upgrade?
While upgrading is the best solution, a temporary workaround is to disable TLS transport, although this may expose the system to security risks.