Apache Camel CVE-2026-40453

Requires that a deployed Camel route (1) consumes from one of the affected transports - camel-jms, camel-sjms, camel-coap, or camel-google-pubsub - and (2) forwards those messages to a header-driven component that honors Camel control headers, specifically camel-exec (OS command execution) or camel-file (file write). The attacker must possess producer access to the broker/topic that route consumes (reflected as PR:L in the CVSS vector) so they can publish a message containing a case-variant Camel internal header such as 'CAmelExecCommandExecutable'. Limiting factors: routes that only consume these transports without chaining to exec/file-style header-driven sinks are not exploitable for RCE; the attacker cannot exploit this with zero access to the messaging layer; and versions at or above 4.20.0 / 4.14.6 / 4.18.2 are not affected. No end-user interaction is required (UI:N).

The signals partly conflict and must be weighed carefully. CVSS 3.1 is 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) and SSVC technical impact is 'total,' consistent with full RCE and arbitrary file write. However, SSVC exploitation is 'none' and automatable is 'no,' EPSS is only 0.06% (18th percentile), there is no KEV listing, and no public exploit code is identified - so despite the near-maximum CVSS this is not currently a mass-exploited threat and leans toward targeted rather than opportunistic risk. Critically, the CVSS is not PR:N: exploitation requires PR:L, i.e. the attacker must already be able to produce messages onto the broker/topic that a vulnerable Camel route consumes, plus the route must forward those messages to a header-driven component like camel-exec or camel-file. Where those preconditions hold the impact is severe and scope-changing (S:C), but they are meaningful gates that keep real-world exposure well below what 9.9 alone implies. Verdict: high priority to patch for anyone running affected components in header-driven routes, but not an immediate drop-everything internet-wide emergency.

An attacker who can publish JMS messages to a queue consumed by a vulnerable Camel route crafts a message carrying a case-variant control header such as 'CAmelExecCommandExecutable' set to '/bin/sh -c ...'. The case-sensitive filter fails to strip it, the case-insensitive Exchange lookup in camel-exec resolves it as the canonical executable header, and the route runs the attacker-chosen command; the same technique against camel-file yields arbitrary file write. No public exploit code is identified at time of analysis, and the low AC/no-UI vector means a single crafted message suffices once producer access exists.