Summary
Apache Camel-Atmosphere-Websocket: WebSocket dispatch header injection - the producer selected its target peers through Exchange headers whose names sat outside the filtered Camel namespace
Improper input validation vulnerability in Apache Camel Atmosphere Websocket component.
This issue affects Apache Camel: from 4.0.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.22.0.
The camel-atmosphere-websocket producer selects which connected WebSocket peers a message is delivered to through Exchange headers, and the string values of those headers sat outside the Camel namespace: websocket.connectionKey and websocket.connectionKey.list, along with websocket.sendToAll, websocket.eventType and websocket.errorType. WebsocketEndpoint extends ServletEndpoint and so inherits HttpHeaderFilterStrategy, which filters only the Camel and camel prefixes; the dotted names therefore fell outside the filtered namespace and were admitted in both directions by every HTTP-family consumer. In a route bridging an HTTP consumer into an atmosphere-websocket producer, an external sender could supply the list header and take over the producer's dispatch decision. WebsocketProducer.process tests the list header before the single-key header, so an injected value discarded the recipient the route had selected: a notification intended for one connected client could be suppressed, or delivered instead to a different client whose connection key the sender knows. The header need not be a query parameter and need not be supplied as a list literally - Camel's HTTP binding promotes a repeated header name, and a bracketed value, to a List when mapping onto the Exchange - so an ordinary inbound HTTP header is sufficient to reach the list-valued branch. This is distinct from CVE-2026-55993, which concerns the consumer-side query-parameter path in the same component. The behaviour dates back to the introduction of these constants, first released in 2.17.0, and was unchanged until this fix.
Users are recommended to upgrade to version 4.22.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.9. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.4. For deployments that cannot upgrade immediately, strip the dispatch headers at the trust boundary before the producer, for example with removeHeaders(“websocket.*”) placed between the HTTP consumer and the atmosphere-websocket producer. Note that the fix renames the header string values into the Camel namespace, which is a breaking change for routes that set them by literal string: routes referencing the WebsocketConstants fields symbolically are unaffected, and the change is documented in the upgrade guides. As defence in depth, do not bridge an untrusted HTTP consumer directly into a WebSocket producer whose dispatch is header-driven without stripping the dispatch namespace first.
Impact
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
CVE-2026-71300 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.14.9, 4.18.4, 4.22.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
org.apache.camel:camel-atmosphere-websocket to 4.14.9 or later; org.apache.camel:camel-atmosphere-websocket to 4.18.4 or later; org.apache.camel:camel-atmosphere-websocket to 4.22.0 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-71300? CVE-2026-71300 is a critical-severity improper input validation vulnerability in org.apache.camel:camel-atmosphere-websocket (maven), affecting versions >= 4.0.0, < 4.14.9. It is fixed in 4.14.9, 4.18.4, 4.22.0. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is CVE-2026-71300? CVE-2026-71300 has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.apache.camel:camel-atmosphere-websocket are affected by CVE-2026-71300? org.apache.camel:camel-atmosphere-websocket (maven) versions >= 4.0.0, < 4.14.9 is affected.
- Is there a fix for CVE-2026-71300? Yes. CVE-2026-71300 is fixed in 4.14.9, 4.18.4, 4.22.0. Upgrade to this version or later.
- Is CVE-2026-71300 exploitable, and should I be worried? Whether CVE-2026-71300 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-71300 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-71300?
- Upgrade
org.apache.camel:camel-atmosphere-websocketto 4.14.9 or later - Upgrade
org.apache.camel:camel-atmosphere-websocketto 4.18.4 or later - Upgrade
org.apache.camel:camel-atmosphere-websocketto 4.22.0 or later
- Upgrade