CVE-2026-84176: Apache Camel: Camel-Platform-HTTP-Vertx Cross-Origin Credential Exposure via Wildcard Origin Reflection

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-19 · updated 2026-10-19
Weakness: CWE-942

Description

Permissive Cross-domain Policy with Untrusted Domains vulnerability in Apache Camel Platform HTTP Vertx component. This issue affects Apache Camel: from 4.0.0 before 4.18.5, from 4.19.0 before 4.22.1. createCorsHandler() set Access-Control-Allow-Credentials: true outside the origin check, so the header went out on every response to a request carrying an Origin header, including responses to origins the handler had just decided not to allow. When camel.server.cors.origins is unset, the handler treats every origin as allowed and echoes the caller's own Origin back as Access-Control-Allow-Origin. Together those produce the credentialed any-origin configuration that the fetch specification refuses to express as a literal wildcard, which is precisely why reflecting the origin is the usual way around that rule. A page on any origin could therefore make credentialed cross-origin requests to the Camel endpoint and read the responses. Upgrade to Apache Camel 4.23.0, which fixes the issue. Users on the 4.18.x LTS releases stream should upgrade to 4.18.5. Users on the 4.22.x LTS releases stream should upgrade to 4.22.1. Access-Control-Allow-Credentials is now sent only when the request origin matched an origin the operator actually configured. With no origin list the origin is still reflected, as before, but credentials are not granted, and Vary: Origin is now set whenever the origin is reflected so that a shared cache cannot serve one origin's response to another. For deployments that cannot upgrade immediately, set camel.server.cors.origins to the explicit list of origins that need access rather than leaving it unset.

Affected products

Apache Software Foundation Apache Camel: from 4.0.0 before 4.18.5; from 4.19.0 before 4.22.1 — fixed in 4.18.5, 4.22.1

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Camel 4.18.5, 4.22.1. Check the vendor advisory for mitigations.

References

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