CVE-2026-66907: CWE-23 Relative path traversal in Apache Software Foundation Apache Camel

The Apache Camel Google Storage consumer downloads objects to the local filesystem when the downloadFileName option is set. If downloadFileName contains no expression token, the consumer appends the remote object name directly to it without lexical normalization or containment checks. Google Cloud Storage object names can include parent-directory segments (e.g., '../'), which are not sanitized or restricted by default. This allows an attacker who can influence object names in the bucket to cause Camel to write files outside the intended directory, potentially overwriting critical files with the privileges of the Camel process. The vulnerability affects Apache Camel versions >=4.0.0 <4.14.9, >=4.15.0 <4.18.4, and >=4.19.0 <4.22.0. The issue is fixed in versions 4.14.9, 4.18.4, and 4.22.0. Mitigations include upgrading to fixed versions, setting the filter option to restrict object names to simple single-segment names, or using an explicit downloadFileName expression that does not propagate the remote path.

An attacker able to control or influence object names in a Google Cloud Storage bucket consumed by Apache Camel can cause arbitrary files to be created or overwritten on the local filesystem outside the intended directory. This can lead to loss of integrity of local files and potentially escalate to further compromise depending on the privileges of the Camel process and the files overwritten. The vulnerability does not affect the producer side or other Camel file-download consumers, only the camel-google-storage consumer.

A fix is available in Apache Camel versions 4.14.9, 4.18.4, and 4.22.0. Users are strongly recommended to upgrade to one of these versions. For deployments that cannot upgrade immediately, set the filter option to a regular expression that only accepts simple single-segment object names, excluding any names with path separators or parent-directory segments. Alternatively, configure downloadFileName with an explicit expression that uses ${file:onlyname} instead of the implicit ${file:name} to avoid propagating remote paths. Treat object names in externally writable buckets as untrusted input and avoid deriving local filesystem paths directly from them.