Deserialization of untrusted data in Apache Kafka

This security bulletin contains one medium risk vulnerability.

EUVDB-ID: #VU112255

Risk: Medium

CVSSv4.0:

6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID:
CVE-2025-27818

CWE-ID:
CWE-502 – Deserialization of Untrusted Data

Exploit availability:
No

Description

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data. A remote user can set the sasl.jaas.config property for connector’s Kafka clients to ‘com.sun.security.auth.module.LdapLoginModule’ through various override properties (producer.override.sasl.jaas.config, consumer.override.sasl.jaas.config, or admin.override.sasl.jaas.config). This configuration enables the server to connect to an attacker’s LDAP server and deserialize the LDAP response, potentially leading to the execution of java deserialization gadget chains on the Kafka connect server.

Mitigation

Install update from vendor’s website.

Vulnerable software versions

Apache Kafka:
2.2.2 – 3.8.1

CPE2.3

External links

kafka.apache.org/cve-list
www.openwall.com/lists/oss-security/2025/06/09/2

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.