CVE-2026-66907: Apache Camel: Camel-Google-Storage: the consumer appended the remote object name to the configured downloadFileName directory without constraining the result

[Andrea Cosentino <acosentino () apache org>]

Severity: moderate 

Affected versions:

- Apache Camel (org.apache.camel:camel-google-storage) 4.0.0 before 4.14.9
- Apache Camel (org.apache.camel:camel-google-storage) 4.15.0 before 4.18.4
- Apache Camel (org.apache.camel:camel-google-storage) 4.19.0 before 4.22.0

Description:

Relative path traversal vulnerability in Apache Camel Google Storage 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-google-storage consumer downloads Google Cloud Storage objects to the local filesystem when the 
downloadFileName option is set. That option is documented as a folder or a filename, and when its value contains no 
expression token the consumer builds the local destination by appending the object name to it: evaluateFileExpression 
sets the Exchange file-name header to the remote object name and evaluates downloadFileName + "/${file:name}". The 
${file:name} token returns the file-name header verbatim, unlike ${file:onlyname}, which applies FileUtil.stripPath to 
it. The resulting string was passed directly to new File(result) and blob.downloadTo(file.toPath()) with no lexical 
normalization and no check that the destination stayed inside the configured directory. The object name is not 
route-controlled data: the consumer lists the bucket, iterates every returned blob and creates one exchange per object 
from blob.getBlobId().getName() verbatim, and the filter option that could restrict those names is not applied at all 
unless it has been explicitly set. Google Cloud Storage object names are opaque UTF-8 keys that the service stores and 
lists exactly as written, with no server-side canonicalization, and a forward slash is only a display convention for 
pseudo-directories, so a key containing parent-directory segments survives round-tripping intact. An object name 
containing such segments therefore resolved to a location outside the configured downloadFileName directory, letting 
anyone able to influence the names present in the consumed bucket cause Camel to create or overwrite a file at a 
location of their choosing, with the privileges of the Camel process. Depending on what the process can write to, 
overwriting a file outside the download directory can escalate beyond the loss of integrity of that file. The 
downloadFileName option is an ordinary consumer parameter and carries no security marker, so nothing signalled to users 
that its value was not being enforced as a containment boundary. The defect is consumer-only; the producer has no 
download-to-file sink. Camel's other file-download consumers - camel-file, camel-ftp, camel-smb, camel-mina-sftp, 
camel-azure-files and the Azure Storage download paths - already constrained their local downloads to the configured 
directory using a path-segment boundary check; camel-google-storage was the remaining object-store download sink not 
covered by that work.



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, set the filter option to a regular 
expression that accepts only simple single-segment object names, so that any name carrying a path separator or a 
parent-directory segment is excluded before an exchange is created; note that no filtering whatsoever is applied when 
the option is left unset, and that the expression is matched against the whole object name. Alternatively, give 
downloadFileName an explicit expression that does not carry the remote path through, for example one built on 
${file:onlyname} rather than the implicit ${file:name}, keeping in mind that a downloadFileName containing an 
expression is treated as route-author-controlled and is not covered by the containment check added in the fix. As 
defence in depth, treat the object names in any externally writable bucket as untrusted input and do not derive local 
filesystem paths from them.

Credit:

n0mi1k (finder)
Andrea Cosentino (remediation developer)

References:

https://camel.apache.org/security/CVE-2026-66907.html
https://camel.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-66907