CVE-2026-88016: rclone: Directory metadata (chmod/chown/chtimes) applied through a planted symlink in rclone local --links escapes the destination
rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, when backend/local runs with --links, a source .rclonelink object can plant a symlink in the destination and later directory metadata is applied through that path. MkdirMetadata, writeMetadataToFile, and setTimes operate when Directory.translatedLink=false, so os.Chown, os.Chmod, os.Chtimes, and birth-time handling can bypass os.Root confinement and follow the symlink. An attacker controlling source contents can therefore apply selected ownership, permissions, modification times, or birth times to a file or directory outside the destination, with --metadata required for chmod and chown while modification time is applied by the normal directory workflow. This issue is fixed in version 1.75.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.75.1
Event History
Frequently Asked Questions
What conditions are required for exploitation?
An attacker must control source contents and be able to provide a .rclonelink object that plants a symlink in the destination. The affected operation must use the local backend with --links enabled; changing ownership or permissions additionally requires --metadata.
Which metadata can be changed outside the destination?
The attacker can cause selected ownership, permissions, modification times, or birth times to be applied to a file or directory outside the destination. Modification times can be applied through the normal directory workflow, while chmod and chown require --metadata.
Who is exposed?
Deployments that copy or sync attacker-controlled source content to a local destination using rclone local --links are exposed. The impact extends beyond the intended destination because metadata operations can follow a planted symlink despite os.Root confinement.
What is the remediation?
Upgrade rclone to version 1.75.1, which fixes the issue. If upgrading is not immediately possible, avoid running the local backend with --links on untrusted source content; also avoid --metadata where possible to prevent chmod and chown changes.