CVE-2026-49097: Apache Camel IRC Header Injection – Message Redirection Vulnerability

Technical summary

The Apache Camel IRC component fails to validate the origin and safety of control headers when they arrive via HTTP ingress. Specifically, headers like 'irc.sendTo', 'irc.target', 'irc.messageType', and related 'irc.user.*' fields lack the Camel namespace prefix (which would be 'CamelIrc*'). Because they do not match the 'Camel' or 'camel' prefix pattern, the HttpHeaderFilterStrategy—designed to block Camel-namespaced headers at HTTP boundaries—allows them to pass through from untrusted HTTP clients directly into the Exchange object. When the IRC producer reads these headers, it uses them to determine the message destination, allowing an HTTP client to override the endpoint's configured channel and redirect outbound IRC traffic to an arbitrary destination. The root cause is improper input validation of untrusted headers and inadequate namespace isolation of IRC control directives.

Business impact

Organizations deploying Camel-based integration routes that bridge web traffic into IRC channels face message exfiltration and impersonation risks. Sensitive data intended for internal channels may leak to public channels or attacker-controlled IRC users. Automated bots may be manipulated to send messages that appear legitimate, damaging trust and potentially facilitating social engineering or coordination of attacks. The impact is highest for environments relying on IRC for operational communication or bot-driven monitoring alerts.

Affected systems

Apache Camel versions 4.0.0 through 4.14.7, versions 4.15.0 through 4.18.2, and versions 4.19.0 through 4.20.x are affected. Notably, the LTS release stream 4.14.x is vulnerable up to 4.14.7. The vulnerability applies to any deployment that combines an HTTP consumer (such as platform-http) with an irc: producer in the same route without additional header filtering.

Exploitability

Exploitation is straightforward and requires no authentication when the HTTP consumer is unauthenticated. An attacker simply adds 'irc.sendTo' or similar IRC control headers to an HTTP request, which Camel will honor. No exploit code, advanced techniques, or credential compromise is necessary. The barrier to exploitation is low, and any organization exposing an HTTP endpoint connected to an IRC producer is at risk. CVSS 3.1 score of 6.5 (Medium) reflects the network-accessible nature and lack of required privileges, offset by limited impact scope (confidentiality and integrity but not availability).

Remediation

Upgrade Apache Camel immediately to version 4.21.0 (general releases), 4.14.8 (LTS stream 4.14.x), or 4.18.3 (release stream 4.18.x). After upgrading, refactor routes to use the Camel-namespaced header names (e.g., 'CamelIrcSendTo') instead of the legacy 'irc.*' names. Organizations unable to patch immediately should add a removeHeaders('irc.*') filter at the start of routes that accept external HTTP input, ensuring untrusted clients cannot inject IRC control headers. Additionally, always set the IRC destination from a trusted, authenticated source rather than from client-supplied headers.

Patch guidance

Verify against the Apache Camel official advisory for exact version requirements, but upgrade paths are: (1) If on 4.0.0–4.14.7, upgrade to 4.14.8 or later; (2) If on 4.15.0–4.18.2, upgrade to 4.18.3 or later; (3) If on 4.19.0 or later, upgrade to 4.21.0 or later. After patching, audit all Camel routes using the irc: component and replace legacy 'irc.*' header references with 'CamelIrc*' equivalents (e.g., 'irc.sendTo' becomes 'CamelIrcSendTo'). Test routes in a staging environment before production rollout.

Detection guidance

Monitor HTTP logs and Camel route traces for the presence of 'irc.*' or 'CamelIrc*' headers in requests from external sources. Implement runtime inspection of Exchange headers in routes bridging HTTP to IRC, logging any case where irc.sendTo or similar control headers appear in untrusted input. Alert on mismatches between the configured IRC channel destination and the actual destination where messages are sent. Threat hunting should focus on routes using older Camel versions (pre-4.21) combined with unauthenticated HTTP consumers.

Why prioritize this

Although CVSS severity is Medium (6.5), this vulnerability warrants expedited patching because it requires no authentication, no user interaction, and affects message confidentiality and integrity in real-time communication. Organizations relying on IRC for operational alerts or sensitive discussions are at elevated risk. The attack surface is straightforward to identify (any HTTP-to-IRC bridging route), and the fix is well-documented. Apply patches in the next maintenance window for affected Camel deployments.

Risk score, explained

CVSS 3.1 score of 6.5 reflects: Attack Vector Network (N, +impact), Attack Complexity Low (L, +impact), Privileges Required None (N, +impact), User Interaction None (N, +impact), Scope Unchanged (U), Confidentiality Low (L, +impact), Integrity Low (L, +impact), Availability None (N). The score does not escalate to High because availability is unaffected, and the impact is confined to message content and direction rather than system compromise. However, the ease of exploitation and lack of authentication requirements merit urgent remediation.

Frequently asked questions