Severity: moderate
Affected versions:
- Apache Camel (org.apache.camel:camel-nats) 4.0.0 before 4.14.8
- Apache Camel (org.apache.camel:camel-nats) 4.15.0 before 4.18.3
- Apache Camel (org.apache.camel:camel-nats) 4.19.0 before 4.21.0
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.
Credit:
Yu Bao from PayPal (finder)
References:
https://camel.apache.org/security/CVE-2026-46457.html
https://camel.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-46457
