Multiple critical security vulnerabilities have been identified in the rclone sync tool package, posing significant risks to cloud storage integrity and host system security. These flaws span path traversal, credential exposure, unauthorized command execution, and denial of service across multiple protocol backends. Exploitation allows remote attackers to breach isolated storage environments, overwrite arbitrary system files, and escalate local privileges. With severe impact potential ranging up to high severity across enterprise infrastructure, immediate patch deployment and configuration auditing are strongly advised. Enterprise environments deploying cloud synchronization tasks face elevated risks of unauthorized data access and compromise.
CVE-2026-71309: An incomplete path validation flaw exists within the serve restic backend component of the application. Attackers can leverage malformed path inputs to bypass storage directory restrictions and escape the designated repository root. Successful exploitation allows unauthorized reading and writing of host filesystem resources outside the intended scope. Threat actors can exploit this weakness remotely to compromise underlying server operating system assets.[/subscribe_to_unlock_form]
Multiple critical security vulnerabilities have been identified in the rclone sync tool package, posing significant risks to cloud storage integrity and host system security. These flaws span path traversal, credential exposure, unauthorized command execution, and denial of service across multiple protocol backends. Exploitation allows remote attackers to breach isolated storage environments, overwrite arbitrary system files, and escalate local privileges. With severe impact potential ranging up to high severity across enterprise infrastructure, immediate patch deployment and configuration auditing are strongly advised. Enterprise environments deploying cloud synchronization tasks face elevated risks of unauthorized data access and compromise.
CVE-2026-71309: An incomplete path validation flaw exists within the serve restic backend component of the application. Attackers can leverage malformed path inputs to bypass storage directory restrictions and escape the designated repository root. Successful exploitation allows unauthorized reading and writing of host filesystem resources outside the intended scope. Threat actors can exploit this weakness remotely to compromise underlying server operating system assets.[emaillocker id="1283"]
CVE-2026-54572: An unvalidated symlink target vulnerability affects the local backend when utilizing specific link handling flags. Untrusted remote repositories can plant malicious symbolic links that resolve outside the local target directory. Upon processing, the application performs arbitrary file writes to restricted system locations without proper authorization. Attackers can use this vector to modify critical binaries or configurations on host machines.
CVE-2026-71310: An resource management issue in the HTTP handling engine leads to unbounded header processing during CONNECT requests. Remote endpoints can stream excessive HTTP response headers to consume all available heap memory. This condition triggers an unrecoverable out-of-memory crash, resulting in a persistent denial of service state. Infrastructure processing untrusted web traffic is particularly susceptible to operational disruption.
CVE-2026-71311: A protocol handling flaw permits CRLF injection in the FTP component when custom encoding configurations retain newline characters. Malicious inputs inject raw FTP commands into the active control session context. This manipulation allows adversaries to alter session behavior, execute unauthorized protocol commands, or disrupt data transfers. System operations relying on custom-encoded FTP configurations are directly exposed.
CVE-2026-71312: An input sanitization failure involving PowerShell smart-quote characters affects command construction in the SFTP backend. Crafted filenames bypass escaping mechanisms during execution on host environments. Remote attackers can leverage this weakness to achieve server-side command execution within the security context of the service account. This significantly increases the risk of complete host takeover and lateral movement.
CVE-2026-59733: An authorization bypass flaw exists within the private repository handling mechanism of the restic service interface. By supplying directory traversal sequences in requested URL paths, authenticated users can cross tenant boundaries. Exploitation allows malicious actors to inspect, overwrite, or permanently delete repositories belonging to other users. This compromise degrades multi-tenant storage isolation controls completely.
CVE-2026-59732: A path traversal flaw in the archive extraction sub-component enables destination prefix escape when unpacking files to S3 backends. Specially crafted archive entries allow files to be written outside the assigned object key prefix. Attackers can exploit this to overwrite critical object data in adjacent S3 buckets or paths. The vulnerability severely undermines cloud storage boundary enforcement.
CVE-2026-71313: A path traversal vulnerability exists within the local path encoding logic when parsing malicious path inputs. The application fails to strictly restrict file references to the configured working directory. Remote attackers can read or overwrite arbitrary local files accessible to the application process. This facilitates broader access control bypasses across local host storage layers.
Organizations must prioritize immediate remediation to protect storage infrastructure and prevent potential lateral movement. Implementing robust input filtering and strict access controls will further reduce the attack surface across affected endpoints. Continuous monitoring of service logs remains essential for detecting anomalous traversal and execution patterns.
We recommend you to update rclone to version 1.75.0.
The following reports contain further technical details:
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