CVE-2026-66906: Apache Camel: Camel-Azure-Storage-Blob: the downloadBlobToFile operation built the local download target from the remote blob name without constraining it to the configured fileDir

[Andrea Cosentino <acosentino () apache org>]

Severity: moderate 

Affected versions:

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

Description:

Relative path traversal vulnerability in Apache Camel Azure Storage Blob 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-azure-storage-blob component can download an Azure Storage blob to the local filesystem through its 
downloadBlobToFile operation, writing into the directory named by the fileDir endpoint option, which is documented as 
usable from both the producer and the consumer. BlobOperations.downloadBlobToFile built the local target by joining 
fileDir with the remote blob name exactly as the Azure SDK reported it (new File(fileDir, client.getBlobName())) and 
passed the result straight to the SDK download call, with no lexical normalization and no check that the resolved 
location stayed inside fileDir. The blob name is not route-controlled data: the consumer enumerates the container in 
BlobConsumer.createBatchExchangesFromContainer, which lists blobs and creates one exchange per entry from 
BlobItem.getName() verbatim, applying no name filtering by default. A blob name containing parent-directory segments 
therefore resolved to a location outside the configured fileDir, letting anyone able to influence the names present in 
the consumed container 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. Azure Storage blob containers use a flat namespace in which the 
blob name is an opaque key, so a name carrying such segments is stored and listed as given. The fileDir option is an 
ordinary common-group configuration parameter and carries no security marker, so nothing signalled to users that its 
value was not being enforced as a containment boundary. Camel's other file-download consumers - camel-file, camel-ftp, 
camel-smb, camel-mina-sftp and camel-azure-files - already constrained their local downloads to the configured 
directory using a path-segment boundary check; the camel-azure-storage-blob download path was 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, constrain the names the consumer will 
act on using the regex endpoint option, which is applied to each listed blob name as a full-string match, so that only 
simple single-segment names are accepted and any name carrying a path separator or a parent-directory segment is 
filtered out before an exchange is created; the prefix option can additionally narrow the listing server-side, noting 
that when both are set regex takes priority and prefix is ignored. Alternatively, avoid the downloadBlobToFile 
operation on untrusted containers and write the payload from the route under a file name the route itself controls, 
rather than one taken from the remote listing. As defence in depth, treat the blob names in any externally writable 
container as untrusted input and do not derive local filesystem paths from them.

Credit:

Hiep Nguyen (finder)
n0mi1k (finder)
Andrea Cosentino (remediation developer)

References:

https://camel.apache.org/security/CVE-2026-66906.html
https://camel.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-66906