CVE-2026-40557

Improper Certificate Validation via Global SSL Context Downgrade in Apache Storm Prometheus Reporter Versions Affected: from 2.6.3 to 2.8.6 Description:  In production deployments where an administrator enables storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation (by default it is disabled) intending to affect only the Prometheus reporter, the undocumented global side effect creates an attack surface across every TLS-protected communication channel in the Storm daemon. The PrometheusPreparableReporter class implements an INSECURE_TRUST_MANAGER that accepts all SSL certificates without validation, with empty checkClientTrusted and checkServerTrusted methods. Most critically, when the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation configuration option is enabled (default = disabled) for HTTPS Prometheus PushGateway connections, the INSECURE_CONNECTION_FACTORY calls SSLContext.setDefault(sslContext), which globally replaces the JVM's default SSL context rather than applying the insecure context only to the Prometheus connection. This payload flows through storm.yaml configuration → PrometheusPreparableReporter.prepare() → INSECURE_CONNECTION_FACTORY → SSLContext.setDefault(), resulting in a JVM-wide TLS security downgrade. All subsequent HTTPS connections in the process - including ZooKeeper, Thrift, Netty, and UI connections - silently trust all certificates, including self-signed, expired, and attacker-generated ones, enabling man-in-the-middle interception of cluster state, topology submissions, tuple data, and administrative credentials. Mitigation: 2.x users should upgrade to 2.8.7 if the Prometheus Metrics Reporter is used. Prometheus Metrics Reporter Users who cannot upgrade immediately should remove the storm.daemon.metrics.reporter.plugin.prometheus.skip_tls_validation: true setting from their storm.yaml configuration and instead configure a proper truststore containing the PushGateway's certificate.
References
Link Resource
https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq Mailing List Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/25/2 Mailing List Third Party Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:apache:storm_prometheus_reporter:*:*:*:*:*:*:*:*

History

05 May 2026, 18:11

Type Values Removed Values Added
CPE cpe:2.3:a:apache:storm_prometheus_reporter:*:*:*:*:*:*:*:*
References () https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq - () https://lists.apache.org/thread/f5bv68z1y5xstz22psjk05p3wn86knjq - Mailing List, Vendor Advisory
References () http://www.openwall.com/lists/oss-security/2026/04/25/2 - () http://www.openwall.com/lists/oss-security/2026/04/25/2 - Mailing List, Third Party Advisory
First Time Apache storm Prometheus Reporter
Apache

30 Apr 2026, 16:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 4.8

27 Apr 2026, 14:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-04-27 14:16

Updated : 2026-06-17 10:45


NVD link : CVE-2026-40557

Mitre link : CVE-2026-40557

CVE.ORG link : CVE-2026-40557


JSON object : View

Products Affected

apache

  • storm_prometheus_reporter
CWE
CWE-295

Improper Certificate Validation