CVE-2026-33557

CriticalCVSS 9.1/10Last modified Jul 15, 2026

Description

A possible security vulnerability has been identified in Apache Kafka.

By default, the broker property `sasl.oauthbearer.jwt.validator.class` is set to `org.apache.kafka.common.security.oauthbearer.DefaultJwtValidator`. It accepts any JWT token without validating its signature, issuer, or audience. An attacker can generate a JWT token from any issuer with the `preferred_username` set to any user, and the broker will accept it.

We advise the Kafka users using kafka v4.1.0 or v4.1.1 to set the config `sasl.oauthbearer.jwt.validator.class` to `org.apache.kafka.common.security.oauthbearer.BrokerJwtValidator` explicitly to avoid this vulnerability. Since Kafka v4.1.2 and v4.2.0 and later, the issue is fixed and will correctly validate the JWT token.

Metrics

CVSS 3.1 9.1/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weakness enumeration

CWE-1285 CWE-303

Affected software

No affected versions have been published.

Timeline

Published: Apr 20, 2026
Last modified: Jul 15, 2026
NVD status: Modified

Related CVEs from 2026

CVE-2026-335585.3Information exposure vulnerability has been identified in Apache Kafka. The NetworkClient component will output entire requests and respons CVE-2026-335595.1WordPress Plugin "OpenStreetMap" provided by MiKa contains a cross-site scripting vulnerability. On the site with the affected version of th CVE-2026-33569.3The MS27102A Remote Spectrum Monitor is vulnerable to an authentication bypass that allows unauthorized users to access and manipulate its m CVE-2026-335608.8The DMP-5000 file service exposes authenticated arbitrary file upload functionality. There are exposed endpoints which allows authenticated CVE-2026-335653.3in OpenHarmony v6.0 and prior versions allow a local attacker cause DOS.CVE-2026-335665.1There is a cypher injection issue in LogonTracer prior to v2.0.0. If specially crafted Windows event log data is loaded, the contents of the CVE-2026-335689.1A OS command injection vulnerability exists in the boa formMapDelDevice macstr functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.CVE-2026-335696.5Anviz CX2 Lite and CX7 administrative sessions occur over HTTP, enabling on‑path attackers to sniff credentials and session data, which can CVE-2026-33578.8IBM Langflow Desktop 1.6.0 through 1.8.2 Langflow could allow an authenticated user to execute arbitrary code on the system, caused by an in CVE-2026-335705.7PowerSYSTEM Center REST API endpoint for devices allows a low privilege authenticated user to access information normally limited by operati CVE-2026-335725.5OpenClaw before 2026.2.17 creates session transcript JSONL files with overly broad default permissions, allowing local users to read transcr CVE-2026-335738.8OpenClaw before 2026.3.11 contains an authorization bypass vulnerability in the gateway agent RPC that allows authenticated operators with o