Apache Storm TLS Client Auth Fail-Open (2.8.7)
CVE-2026-41081 Published on April 27, 2026

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

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-41081 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
LOW
Integrity Impact:
LOW
Availability Impact:
NONE

Weakness Type

What is an authentification Vulnerability?

When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.

CVE-2026-41081 has been classified to as an authentification vulnerability or weakness.


Affected Versions

Apache Software Foundation Apache Storm Client: