Apache Kafka up to 4.1.2/4.2.1/4.3.1 Configuration Validation improper authorization

Summaryinfo

A vulnerability categorized as problematic has been discovered in Apache Kafka up to 4.1.2/4.2.1/4.3.1. This issue affects some unknown processing of the component Configuration Validation. The manipulation results in improper authorization. This vulnerability was named CVE-2026-112375. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Apache Kafka up to 4.1.2/4.2.1/4.3.1. Affected is an unknown functionality of the component Configuration Validation. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality. CVE summarizes:

An authenticated Kafka principal with no authorization grants (not even ALTER_CONFIGS) can make a broker read a file or an environment variable from the broker host and return its contents. An IncrementalAlterConfigs (or AlterConfigs) request targeting a BROKER resource reaches the broker's configuration validation before any authorization check is applied to that path. Validation resolves configuration variables such as ${file:/path:key} or ${env:VAR} using a ConfigProvider named in the request, and this resolution bypasses the org.apache.kafka.automatic.config.providers allowlist that was added as the mitigation for CVE-2024-31141. An arbitrary ConfigProvider (for example FileConfigProvider or EnvVarConfigProvider) is therefore instantiated and the referenced file or environment variable is read, and a type-validation error returns the resolved content to the caller. Impact: On a cluster with an authorizer enabled, an authenticated principal with no authorization grants can read the contents of files accessible to the broker process, and the broker's environment variables, exposing credentials, keystores, or other secrets, defeating the CVE-2024-31141 allowlist. The read is bounded by the broker process's file permissions. The brokers and the cluster remain available; the issue is disclosure of file and environment- variable contents. Clusters with no authorizer configured are not affected in practice, because every principal already holds ALTER_CONFIGS there. Mitigation: Upgrade to Apache Kafka 4.2.2, 4.3.2, or 4.4.0. As defense in depth, run brokers under a least-privileged operating-system account so that sensitive files are not readable by the broker process. Resolution: From Apache Kafka 4.2.2, 4.3.2, and 4.4.0: broker configuration changes are authorized (ALTER_CONFIGS on the cluster) before the configuration is validated, and configuration- variable resolution enforces the config-providers allowlist.

The advisory is available at kafka.apache.org. This vulnerability is traded as CVE-2026-112375 since 10/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/28/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

Upgrading to version 4.2.2, 4.3.2 or 4.4.0 eliminates this vulnerability.

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Productinfo

Vendor

• Apache

Name

• Kafka

Version

• 4.1.0
• 4.1.1
• 4.1.2
• 4.2.0
• 4.2.1
• 4.3.0
• 4.3.1

License

• open-source

Website

• Vendor: https://www.apache.org/

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