Aven-Open Karapace is an open‑source implementation of Kafka REST and Schema Registry. In versions prior to 6.0.0, the backup reader component contains a path traversal flaw that allows a malicious backup file to be processed with insufficient path validation, enabling arbitrary files on the host where Karapace runs to be read. Depending on the file system permissions granted to the Karapace process, an attacker could access configuration files, secrets, or other sensitive data, resulting in information disclosure.

The vulnerability affects all deployments of Aiven‑Open Karapace versions before 6.0.0 that use the backup/restore feature and are exposed to untrusted backup files. It is present in the file karapace/backup/backends/v3/backend.py. Users should verify the running version and plan an upgrade.

The CVSS score of 4.1 indicates moderate severity, and the EPSS score of less than 1% reflects a low likelihood of exploitation in the wild. The vulnerability is not listed in the CISA KEV catalog. Exploitation requires the ability to supply a crafted backup file to Karapace; if the backup endpoint is reachable over a network, the attack could be performed remotely. Karapace version 6.0.0 contains a fix that removes the path validation flaw.