Apache Camel Security Advisory - CVE-2026-55993

Apache Camel security advisory: CVE-2026-55993

Severity

HIGH

Summary

Camel-Atmosphere-Websocket: The inbound consumer maps externally-supplied WebSocket query parameters into the Exchange without a HeaderFilterStrategy, allowing injection of Camel control headers - enabling server-side request forgery and disclosure of secrets when bridged to an HTTP producer

Versions affected

From 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0.

Versions fixed

4.14.8, 4.18.3 and 4.21.0

Description

The camel-atmosphere-websocket consumer mapped inbound WebSocket query parameters into the Camel Exchange header map without applying any HeaderFilterStrategy (WebsocketConsumer.sendEventNotification() iterates the query-string map collected in WebsocketConsumer.service() and copies each entry into the Exchange). Because nothing blocked the Camel header namespace, a client connecting to the WebSocket endpoint could set Camel-internal control headers - including CamelHttpUri (Exchange.HTTP_URI) - simply by supplying them as query parameters. In a route where the WebSocket consumer feeds a downstream HTTP producer, the injected CamelHttpUri redirects the server-side HTTP request to an attacker-chosen destination (server-side request forgery - for example to an internal service or a cloud metadata endpoint). In addition, the HTTP producer resolves Camel property placeholders on the resulting (attacker-controlled) URI, so placeholders embedded in the injected value - such as an environment-variable reference, an application property, or a vault reference - are resolved to their real values and sent to the attacker, disclosing environment variables, application properties and vault secrets. When the WebSocket endpoint is exposed without authentication, this is reachable by an unauthenticated remote attacker.

Notes

The JIRA ticket: https://issues.apache.org/jira/browse/CAMEL-23532 refers to the various commits that resolved the issue, and have more details. The fix was merged on main in https://github.com/apache/camel/pull/23285 (commit 1e776238202edb9d98972cff558e12b53e499647) and backported to camel-4.18.x (commit 88c43e3af36013585b5483c671950f30e5833a5f) and camel-4.14.x (commit 508fc15deca97ba373eb3881a00e220eab9ec428). The fix makes the camel-atmosphere-websocket consumer apply the HeaderFilterStrategy it already inherits from the HTTP/servlet stack (HttpHeaderFilterStrategy), filtering the Camel header namespace case-insensitively on inbound mapping, so attacker-supplied Camel* / camel* headers are no longer copied into the Exchange; a headerFilterStrategy endpoint option was already available. The issue is classified as CWE-20 (Improper Input Validation), with the resulting impact when the consumer is bridged to a downstream HTTP producer being CWE-918 (Server-Side Request Forgery) and CWE-200 (Exposure of Sensitive Information). It belongs to the same Camel header-injection family as CVE-2025-27636, CVE-2025-29891, CVE-2025-30177, CVE-2026-40453, CVE-2026-46454 and CVE-2026-47323, and shares its fix (CAMEL-23532) with the sibling advisories CVE-2026-46726 (camel-vertx-websocket) and CVE-2026-55994 (camel-iggy).

Mitigation

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 the consumer apply the HeaderFilterStrategy it already inherits from the HTTP/servlet stack, filtering the Camel header namespace case-insensitively on inbound mapping, so externally-supplied Camel* / camel* headers are no longer copied into the Exchange. For deployments that cannot upgrade immediately, strip the Camel control headers from the inbound message before they reach any downstream producer (for example removeHeaders(‘Camel*’) and removeHeaders(‘camel*’) at the start of the route), require authentication on the WebSocket endpoint, and avoid bridging an untrusted consumer directly into an HTTP producer whose target URI can be driven from message headers.

Credit

This issue was discovered by Kamalpreet Singh

References

PGP signed advisory data: CVE-2026-55993.txt.asc
Mitre CVE Entry: https://www.cve.org/CVERecord?id=CVE-2026-55993