CVE-2026-88016

rclone prior to 1.75.1 contains a symlink-following flaw (CWE-59) in the local backend when run with --links: a crafted source .rclonelink object plants a symlink in the destination, and subsequent directory operations (MkdirMetadata, writeMetadataToFile, setTimes) follow that link, bypassing os.Root confinement. An attacker who controls the contents being synced can therefore cause rclone to apply ownership (chown), permissions (chmod), modification times, or birth times to a file or directory outside the intended destination. The impact is limited to metadata tampering rather than arbitrary file content writes, but out-of-bounds permission or time changes can weaken file integrity or mislead other processes; the CVSS 3.1 score is 7.1 (high) with network vector, high attack complexity, low privileges, and user interaction required. Any rclone user syncing from a source with attacker-influenced contents using --links is affected, with --metadata required for the chmod/chown paths while modification-time changes occur in the normal directory workflow. There is no public proof-of-concept, the flaw is not in CISA KEV, and no in-the-wild exploitation has been reported.

What to do: Upgrade to rclone 1.75.1 or later, which fixes the symlink confinement issue. Until patched, avoid using --links when syncing from sources whose contents are attacker-controlled or untrusted, and note that --metadata is required for the chown/chmod path while modification-time changes occur without it. Audit recent sync jobs that used --links for unexpected ownership, permission, or timestamp changes on files adjacent to your destinations.