CVE-2026-116195 in Rclone
Summary
by MITRE • 10/25/2026
Rclone before 1.75.2 contains a path traversal vulnerability in the local backend's translateLink function, which trims the .rclonelink suffix from a path after the containment check, so a name can resolve outside the destination root. Attackers can plant a directory named ...rclonelink in a source tree synced with --links and --metadata to change ownership, timestamps, and xattrs of the destination's parent directory.
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Analysis
by VulDB Data Team • 10/25/2026
The vulnerability identified in Rclone versions prior to 1.75.2 represents a critical path traversal flaw within the local backend implementation, specifically affecting the translateLink function responsible for handling symbolic links during synchronization operations. This security defect arises from an incorrect sequence of validation and processing steps where the system performs containment checks against the destination root directory before stripping specific file extensions. The core technical failure lies in the fact that the .rclonelink suffix is removed only after the path has already been validated as being within the allowed boundaries, creating a window for manipulation where the effective resolved path differs from the checked path. This logic error allows an attacker to craft filenames containing sequences such as ...rclonelink which, once processed by stripping the known extension, resolve to parent directories outside of the intended destination root scope.
From an operational perspective, this vulnerability enables significant unauthorized modifications to file system metadata and ownership structures on the target machine when users employ synchronization flags like --links and --metadata. By planting a directory with the specific malicious naming convention within a source tree that is being synced, an attacker can force Rclone to alter attributes of directories located above the designated sync root. This includes changing file ownership, modifying timestamps, and manipulating extended attributes (xattrs) on parent directories. Such actions compromise the integrity of the local filesystem state beyond the immediate scope of the synchronized data, potentially leading to privilege escalation if combined with other system misconfigurations or affecting critical system files depending on where Rclone is executed.
This flaw aligns closely with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, as it involves failing to properly neutralize special elements within a pathname that could allow access to unintended areas of the file system. Furthermore, in the context of attack tactics, this vulnerability facilitates lateral movement and persistence through manipulation of filesystem metadata, which can be categorized under ATT&CK techniques related to File and Directory Permissions Modification or potentially Taint Shared Components if used to compromise shared resources. The ability to alter ownership and extended attributes is particularly dangerous as it may bypass access control lists or security policies that rely on these specific file properties for enforcement.
To mitigate this risk, organizations must immediately upgrade Rclone to version 1.75.2 or later where the path validation logic has been corrected to ensure containment checks occur after all necessary string manipulations and normalizations are complete. Until an update is applied, administrators should exercise extreme caution when using the --links flag with untrusted source trees, ideally restricting synchronization operations to fully trusted environments only. Additionally, implementing strict input sanitization at the application level or utilizing chroot jails can provide a layer of defense against path traversal attempts by limiting the effective scope of file system access regardless of how paths are resolved internally within the software logic.