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Apache Camel-Kafka: The kafka.OVERRIDE_TOPIC (and other kafka.*) Exchange header constants used non-Camel-prefixed names that bypass the upstream HTTP header filter

Moderate severity GitHub Reviewed Published Jul 6, 2026 to the GitHub Advisory Database • Updated Aug 28, 2026

Package

maven org.apache.camel:camel-kafka (Maven)

Affected versions

>= 4.0.0, < 4.14.8
>= 4.15.0, < 4.18.3
>= 4.19.0, < 4.21.0

Patched versions

4.14.8
4.18.3
4.21.0

Description

Improper Input Validation, Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in Apache Camel Kafka Component.

The camel-kafka producer can override its configured target topic at runtime from the kafka.OVERRIDE_TOPIC Exchange header: KafkaProducer.evaluateTopic() returns the header value in preference to the topic configured on the endpoint. The control-header constants in KafkaConstants (for example OVERRIDE_TOPIC = kafka.OVERRIDE_TOPIC, OVERRIDE_TIMESTAMP = kafka.OVERRIDE_TIMESTAMP, PARTITION_KEY = kafka.PARTITION_KEY) used plain, non-Camel-prefixed values. camel-kafka's own KafkaHeaderFilterStrategy does filter the kafka.* namespace, but only on the Kafka-to-Exchange serialization boundary (reading Kafka record headers into the Exchange, and writing Exchange headers into a Kafka record); it does not apply to headers that arrive from an upstream consumer in a multi-component route. The upstream HTTP consumer uses HttpHeaderFilterStrategy, which blocks only the Camel / camel namespace, so a kafka.* header passes through unfiltered. As a result, in a route that bridges an HTTP consumer (for example platform-http) into a kafka: producer, any HTTP client could set the kafka.OVERRIDE_TOPIC header and cause the message to be published to an arbitrary Kafka topic instead of the configured one - redirecting it to a sensitive internal topic, or injecting attacker-crafted messages into a topic consumed by a critical downstream service. The related kafka.OVERRIDE_TIMESTAMP and kafka.PARTITION_KEY headers could likewise be injected to backdate messages or target specific partitions. No credentials are required when the bridging consumer is unauthenticated.
This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0.

Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. After upgrading, routes that set or read Kafka headers via the raw header names must use the CamelKafka* names (for example CamelKafkaOverrideTopic and CamelKafkaTopic) instead of the old kafka.* values. For deployments that cannot upgrade immediately, strip the kafka.* headers from any untrusted ingress before the kafka: producer (for example removeHeaders('kafka.*') at the start of the route), and set the target topic from a trusted source.

References

Published by the National Vulnerability Database Jul 6, 2026
Published to the GitHub Advisory Database Jul 6, 2026
Reviewed Aug 28, 2026
Last updated Aug 28, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(47th percentile)

Weaknesses

Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Learn more on MITRE.

Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Learn more on MITRE.

CVE ID

CVE-2026-49098

GHSA ID

GHSA-mm84-qvjh-hcj7

Source code

Credits

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