{"schema_version": "1.6.1", "id": "CVE-2026-41081", "summary": "Anonymous principal assigned on TLS client certificate verification failure", "details": "Improper Handling of TLS Client Authentication Failure Leading to Anonymous Principal Assignment in Apache Storm\n\nVersions Affected: up to 2.8.7\n\nDescription: 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.\n\nThis 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.\n\nImpact: Unauthenticated clients may be assigned a principal identity, potentially bypassing authorization in permissive or misconfigured environments.\n\nMitigation: Users should upgrade to 2.8.7 in which TLS authentication failures are handled in a fail-closed manner.\n\nUsers who cannot upgrade immediately should:\n- Enable mandatory client certificate authentication (nimbus.thrift.tls.client.auth.required: true)\n- Ensure authorization rules explicitly deny access to CN=ANONYMOUS\n- Review all ACL configurations for implicit default-allow behavior", "affected": [{"ranges": [{"type": "SEMVER", "events": [{"introduced": "0"}, {"fixed": "2.8.7"}]}]}], "references": [{"type": "WEB", "url": "https://lists.apache.org/thread/plxx5l29dvplk5rwzdcq53rdfl6v4gs8"}]}