Vulnerability in Rclone

CVE-2026-88017

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.64.0 until 1.75.1, the FTP auth-proxy driver in cmd/serve/ftp/ftp.go stores one obscured password per username in the server-wide userPass map[string]string instead of binding the credential or VFS to the authenticated session. If two accepted credentials use the same username but resolve to different proxy backends, a later CheckPasswd login overwrites userPass[user], and subsequent getVFS operations on the first session are reauthorized with the later password. The first session can then read, create, overwrite, rename, or delete objects using the second credential’s backend authority. Exploitation requires the later same-username login to occur while the first session remains open. This issue is fixed in version 1.75.1.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N.

Affected products

  • Rclone — versions >= 1.64.0, < 1.75.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-88017?
CVE-2026-88017 is a high-severity vulnerability in Rclone, classified under CWE-488. CVSS score: 7.3/10. Published 2026-09-10.
How severe is CVE-2026-88017?
High severity. CVSS v3 base score is 7.3 out of 10.