Description
Apache Kafka Connect contains an authentication bypass vulnerability affecting the admin REST API when admin.listeners is configured with a separate listener from the main listeners property.
When operators isolate the admin REST API by explicitly configuring the "admin.listeners" property, REST extensions specified via rest.extension.classes (such as BasicAuthSecurityRestExtension) are not registered or applied to the admin resource configuration.
While the primary REST API listener (configured via listeners) enforces configured authentication and authorization filters, endpoints mounted under the separate admin listener (/admin/loggers) fail to inherit or instantiate these extension filters. As a result, the admin logger endpoint accepts unauthenticated read and write requests even when security extensions are active on the main listener.
Impact:
An unauthenticated attacker with network access to the admin listener can:
1. Read the complete set of logger names and levels, disclosing loaded class names and which security extensions are in use.
2. Write logger levels, including with scope=cluster which propagates the change to all workers in the Connect cluster. This can be used to suppress
logging (setting root to OFF) or generate excessive log output (setting root to TRACE), potentially impacting availability and observability.
Mitigation:
Users who cannot upgrade immediately can remove the admin.listeners configuration (or leave it unset). When unset, admin resources share the regular listener and inherit its security extensions.
Resolution:
From Apache Kafka 4.2.2, 4.3.2, and 4.4.0, we make sure the REST extensions specified via "rest.extension.classes" will also apply to "admin.listeners".
When operators isolate the admin REST API by explicitly configuring the "admin.listeners" property, REST extensions specified via rest.extension.classes (such as BasicAuthSecurityRestExtension) are not registered or applied to the admin resource configuration.
While the primary REST API listener (configured via listeners) enforces configured authentication and authorization filters, endpoints mounted under the separate admin listener (/admin/loggers) fail to inherit or instantiate these extension filters. As a result, the admin logger endpoint accepts unauthenticated read and write requests even when security extensions are active on the main listener.
Impact:
An unauthenticated attacker with network access to the admin listener can:
1. Read the complete set of logger names and levels, disclosing loaded class names and which security extensions are in use.
2. Write logger levels, including with scope=cluster which propagates the change to all workers in the Connect cluster. This can be used to suppress
logging (setting root to OFF) or generate excessive log output (setting root to TRACE), potentially impacting availability and observability.
Mitigation:
Users who cannot upgrade immediately can remove the admin.listeners configuration (or leave it unset). When unset, admin resources share the regular listener and inherit its security extensions.
Resolution:
From Apache Kafka 4.2.2, 4.3.2, and 4.4.0, we make sure the REST extensions specified via "rest.extension.classes" will also apply to "admin.listeners".
Published:
2026-10-28
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Apache Software Foundation | Apache Kafka | unaffected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
| Link | Providers |
|---|---|
| https://kafka.apache.org/cve-list |
|
History
Wed, 28 Oct 2026 17:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Apache Kafka Connect contains an authentication bypass vulnerability affecting the admin REST API when admin.listeners is configured with a separate listener from the main listeners property. When operators isolate the admin REST API by explicitly configuring the "admin.listeners" property, REST extensions specified via rest.extension.classes (such as BasicAuthSecurityRestExtension) are not registered or applied to the admin resource configuration. While the primary REST API listener (configured via listeners) enforces configured authentication and authorization filters, endpoints mounted under the separate admin listener (/admin/loggers) fail to inherit or instantiate these extension filters. As a result, the admin logger endpoint accepts unauthenticated read and write requests even when security extensions are active on the main listener. Impact: An unauthenticated attacker with network access to the admin listener can: 1. Read the complete set of logger names and levels, disclosing loaded class names and which security extensions are in use. 2. Write logger levels, including with scope=cluster which propagates the change to all workers in the Connect cluster. This can be used to suppress logging (setting root to OFF) or generate excessive log output (setting root to TRACE), potentially impacting availability and observability. Mitigation: Users who cannot upgrade immediately can remove the admin.listeners configuration (or leave it unset). When unset, admin resources share the regular listener and inherit its security extensions. Resolution: From Apache Kafka 4.2.2, 4.3.2, and 4.4.0, we make sure the REST extensions specified via "rest.extension.classes" will also apply to "admin.listeners". | |
| Title | Apache Kafka: Connect Admin REST API Authentication Bypass via Unapplied REST Extensions | |
| References |
|
Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: apache
Published:
Updated: 2026-10-28T16:45:36.440Z
Reserved: 2026-10-23T03:48:31.242Z
Link: CVE-2026-115644
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-28T17:18:00.630
Modified: 2026-10-28T17:18:00.630
Link: CVE-2026-115644
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.