---
title: "CVE-2026-71300: 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"
url: https://erroneo.us/security/cve/CVE-2026-71300/
description: "CVE-2026-71300 (org.apache.camel:camel-atmosphere-websocket (Maven)): Improper input validation vulnerability in Apache Camel Atmosphere Websocket…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-24
date_modified: 2026-08-28
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-71300"
kev: false
cvss: 9.8
epss: 0.00738
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-71300: 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

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.7% , percentile 54: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 54% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.apache.camel:camel-atmosphere-websocket (Maven) >= 4.0.0, < 4.14.9, fixed in 4.14.9 ; org.apache.camel:camel-atmosphere-websocket (Maven) >= 4.15.0, < 4.18.4, fixed in 4.18.4 ; org.apache.camel:camel-atmosphere-websocket (Maven) >= 4.19.0, < 4.22.0, fixed in 4.22.0 . Check your lockfile, including transitive dependencies.

## What it is

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…

## Affected packages

- Maven `org.apache.camel:camel-atmosphere-websocket` >= 4.0.0, < 4.14.9 → fixed: 4.14.9
- Maven `org.apache.camel:camel-atmosphere-websocket` >= 4.15.0, < 4.18.4 → fixed: 4.18.4
- Maven `org.apache.camel:camel-atmosphere-websocket` >= 4.19.0, < 4.22.0 → fixed: 4.22.0

## Affected products (CVE record)

- Apache Software Foundation Apache Camel: 4.0.0 < 4.14.9, 4.15.0 < 4.18.4, 4.19.0 < 4.22.0

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.74% probability of exploitation activity in the next 30 days; percentile 54.

## Sources

- [camel.apache.org](https://camel.apache.org/security/CVE-2026-71300.html)
- [GitHub Advisory GHSA-m5r8-w65q-8wjf](https://github.com/advisories/GHSA-m5r8-w65q-8wjf)
- [CVE.org record CVE-2026-71300](https://www.cve.org/CVERecord?id=CVE-2026-71300)
- [NVD entry CVE-2026-71300](https://nvd.nist.gov/vuln/detail/CVE-2026-71300)
- [github.com](https://github.com/apache/camel/pull/25366)
- [github.com](https://github.com/apache/camel/pull/25382)
- [github.com](https://github.com/apache/camel/pull/25383)
- [github.com](https://github.com/apache/camel/pull/25384)
- [github.com](https://github.com/apache/camel/commit/49e197a66158eb7151b461b46b37407df2e13591)
- [github.com](https://github.com/apache/camel/commit/60ca704c0379e6e87107158c0b2174c3f0f2f48a)
- [github.com](https://github.com/apache/camel/commit/66567833fb1efe6d66c6618dbb48295cce4c84ba)
- [github.com](https://github.com/apache/camel/releases/tag/camel-4.14.9)
- [github.com](https://github.com/apache/camel/releases/tag/camel-4.18.4)
- [github.com](https://github.com/apache/camel/releases/tag/camel-4.22.0)
- [issues.apache.org](https://issues.apache.org/jira/browse/CAMEL-24359)

---
Source page: https://erroneo.us/security/cve/CVE-2026-71300/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt