CVE-2026-46457: CWE-20 Improper Input Validation in Apache Software Foundation Apache Camel
Improper Input Validation vulnerability in Apache Camel NATS component. The camel-nats component maps inbound NATS message headers into the Camel Exchange but defaulted its headerFilterStrategy to a bare new DefaultHeaderFilterStrategy() with no inbound rules configured (NatsConfiguration). With no inFilter, inFilterPattern or inFilterStartsWith set, DefaultHeaderFilterStrategy.applyFilterToExternalHeaders returns not filtered for every header name, so NatsConsumer copies every NATS message header - including Camel-internal control headers such as CamelHttpUri, CamelFileName or CamelSqlQuery - unmodified onto the Camel message. A client able to publish to the consumed NATS subject can therefore inject arbitrary Camel control headers that influence the behaviour of downstream producers in the route (for example redirecting an HTTP producer, changing a file name, or overriding a query); the injected headers also persist across internal direct, seda and vm hops. The concrete downstream impact depends on which producers the route uses. NATS message headers require NATS 2.2 or later, and the issue is reachable without credentials when the NATS server is configured without authentication (the NATS server default). 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. The fix makes camel-nats default to a dedicated NatsHeaderFilterStrategy that filters the Camel header namespace case-insensitively on inbound mapping, so client-supplied Camel* / camel* headers are no longer copied into the Exchange. For deployments that cannot upgrade immediately, strip the Camel control headers from inbound NATS messages before they reach any downstream producer (for example removeHeaders('Camel*') and removeHeaders('camel*') at the start of the route), and enable authentication on the NATS server so that only trusted clients can publish to the consumed subject.
AI Analysis
Technical Summary
The vulnerability in Apache Camel's camel-nats component arises because the default header filter strategy does not filter inbound NATS message headers, allowing all headers—including Camel internal control headers—to be copied unmodified into the Camel Exchange. This enables a client publishing to the consumed NATS subject to inject arbitrary Camel control headers that can alter downstream producer behavior in the route, such as redirecting HTTP requests or changing file names. The issue requires NATS 2.2 or later and is reachable without authentication if the NATS server is configured with no authentication (the default). The vulnerability affects Apache Camel versions 4.0.0 up to but not including 4.14.8, 4.15.0 up to but not including 4.18.3, and 4.19.0 up to but not including 4.21.0. The fix, available in 4.21.0 and LTS releases 4.14.8 and 4.18.3, introduces a dedicated NatsHeaderFilterStrategy that filters Camel header namespaces case-insensitively on inbound mapping, preventing client-supplied Camel headers from being copied into the Exchange. For those unable to upgrade immediately, mitigation includes stripping Camel control headers at the start of the route and enabling authentication on the NATS server to restrict publishing to trusted clients.
Potential Impact
An attacker able to publish messages to the NATS subject consumed by Apache Camel can inject arbitrary Camel internal control headers into the message exchange. This can manipulate downstream producers in the route, potentially redirecting HTTP requests, altering file names, or overriding SQL queries. The impact depends on the specific producers used in the route. The vulnerability is exploitable without credentials if the NATS server is configured without authentication, which is the default setting. This can lead to unauthorized control over message routing and processing within Apache Camel routes.
Mitigation Recommendations
A fix is available in Apache Camel versions 4.21.0, 4.14.8 (LTS), and 4.18.3. Users are strongly recommended to upgrade to these versions to address the vulnerability. For deployments that cannot upgrade immediately, it is advised to strip Camel control headers from inbound NATS messages at the start of the route (e.g., using removeHeaders('Camel*') and removeHeaders('camel*')). Additionally, enabling authentication on the NATS server to restrict publishing to trusted clients is recommended to reduce the risk of exploitation.
CVE-2026-46457: CWE-20 Improper Input Validation in Apache Software Foundation Apache Camel
Description
Improper Input Validation vulnerability in Apache Camel NATS component. The camel-nats component maps inbound NATS message headers into the Camel Exchange but defaulted its headerFilterStrategy to a bare new DefaultHeaderFilterStrategy() with no inbound rules configured (NatsConfiguration). With no inFilter, inFilterPattern or inFilterStartsWith set, DefaultHeaderFilterStrategy.applyFilterToExternalHeaders returns not filtered for every header name, so NatsConsumer copies every NATS message header - including Camel-internal control headers such as CamelHttpUri, CamelFileName or CamelSqlQuery - unmodified onto the Camel message. A client able to publish to the consumed NATS subject can therefore inject arbitrary Camel control headers that influence the behaviour of downstream producers in the route (for example redirecting an HTTP producer, changing a file name, or overriding a query); the injected headers also persist across internal direct, seda and vm hops. The concrete downstream impact depends on which producers the route uses. NATS message headers require NATS 2.2 or later, and the issue is reachable without credentials when the NATS server is configured without authentication (the NATS server default). 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. The fix makes camel-nats default to a dedicated NatsHeaderFilterStrategy that filters the Camel header namespace case-insensitively on inbound mapping, so client-supplied Camel* / camel* headers are no longer copied into the Exchange. For deployments that cannot upgrade immediately, strip the Camel control headers from inbound NATS messages before they reach any downstream producer (for example removeHeaders('Camel*') and removeHeaders('camel*') at the start of the route), and enable authentication on the NATS server so that only trusted clients can publish to the consumed subject.
CVSS v3.1
Score 7.5high
Affected software
pkg:maven/Apache Software Foundation/org.apache.camel:camel-natsRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Apache Camel's camel-nats component arises because the default header filter strategy does not filter inbound NATS message headers, allowing all headers—including Camel internal control headers—to be copied unmodified into the Camel Exchange. This enables a client publishing to the consumed NATS subject to inject arbitrary Camel control headers that can alter downstream producer behavior in the route, such as redirecting HTTP requests or changing file names. The issue requires NATS 2.2 or later and is reachable without authentication if the NATS server is configured with no authentication (the default). The vulnerability affects Apache Camel versions 4.0.0 up to but not including 4.14.8, 4.15.0 up to but not including 4.18.3, and 4.19.0 up to but not including 4.21.0. The fix, available in 4.21.0 and LTS releases 4.14.8 and 4.18.3, introduces a dedicated NatsHeaderFilterStrategy that filters Camel header namespaces case-insensitively on inbound mapping, preventing client-supplied Camel headers from being copied into the Exchange. For those unable to upgrade immediately, mitigation includes stripping Camel control headers at the start of the route and enabling authentication on the NATS server to restrict publishing to trusted clients.
Potential Impact
An attacker able to publish messages to the NATS subject consumed by Apache Camel can inject arbitrary Camel internal control headers into the message exchange. This can manipulate downstream producers in the route, potentially redirecting HTTP requests, altering file names, or overriding SQL queries. The impact depends on the specific producers used in the route. The vulnerability is exploitable without credentials if the NATS server is configured without authentication, which is the default setting. This can lead to unauthorized control over message routing and processing within Apache Camel routes.
Mitigation Recommendations
A fix is available in Apache Camel versions 4.21.0, 4.14.8 (LTS), and 4.18.3. Users are strongly recommended to upgrade to these versions to address the vulnerability. For deployments that cannot upgrade immediately, it is advised to strip Camel control headers from inbound NATS messages at the start of the route (e.g., using removeHeaders('Camel*') and removeHeaders('camel*')). Additionally, enabling authentication on the NATS server to restrict publishing to trusted clients is recommended to reduce the risk of exploitation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-05-14T11:45:46.558Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4b6cac27e9c797192522a1
Added to database: 07/06/2026, 08:51:56 UTC
Last enriched: 07/06/2026, 09:09:17 UTC
Last updated: 07/06/2026, 23:08:02 UTC
Views: 5
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