CVE-2025-27819 Apache Kafka: Possible RCE/Denial of service attack via SASL JAAS JndiLoginModule configuration

What is CVE-2025-27819?

CVE-2025-27819 is a high-severity unsafe deserialization vulnerability in Apache Kafka, published on 10 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In CVE-2023-25194, we announced the RCE/Denial of service attack via SASL JAAS JndiLoginModule configuration in Kafka Connect API. But not only Kafka Connect API is vulnerable to this attack, the Apache Kafka brokers also have this vulnerability. To exploit this vulnerability, the attacker needs to be able to connect to the Kafka cluster and have the AlterConfigs permission on the cluster resource.

Since Apache Kafka 3.4.0, we have added a system property ("-Dorg.apache.kafka.disallowed.login.modules") to disable the problematic login modules usage in SASL JAAS configuration. Also by default "com.sun.security.auth.module.JndiLoginModule" is disabled in Apache Kafka 3.4.0, and "com.sun.security.auth.module.JndiLoginModule,com.sun.security.auth.module.LdapLoginModule" is disabled by default in in Apache Kafka 3.9.1/4.0.0

Weakness: CWE-502

Which versions are affected by CVE-2025-27819?

17 open source packages ship an affected version, including org.apache.kafka:kafka_2.10, kafka and org.apache.kafka:kafka_2.11. It affects 1 product.

Products include Apache Kafka.

How do I fix CVE-2025-27819?

Change a configuration setting.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2025-27819 being exploited?

There is no known exploitation of CVE-2025-27819 in the wild and no public exploit code.

Other vulnerabilities in Apache Kafka

• CVE-2026-33557 Apache Kafka: Missing JWT token validation in OAUTHBEARER authentication Critical 9.1
• CVE-2025-27818 Apache Kafka: Possible RCE attack via SASL JAAS LdapLoginModule configuration High 8.8
• CVE-2018-17196 Improper Input Validation in Apache Kafka High 8.8
• CVE-2026-35554 Apache Kafka Clients: Kafka Producer Message Corruption and Misrouting via Buffer Pool Race Condition High 8.7
• CVE-2025-27817 Apache Kafka Client: Arbitrary file read and SSRF vulnerability High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-kafka-2025-27819, GHSA-mcwh-c9pg-xw43.