Exposure of Data Element to Wrong Session in rclone - CVE-2026-88017
Published: September 7, 2026 / Updated: September 12, 2026
Vulnerability identifier: #VU147306
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-88017
CWE-ID: CWE-488
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose and modify data exposed by another backend.
The vulnerability exists due to exposure of a data element to the wrong session in the FTP auth-proxy driver's username-global credential map when handling subsequent FTP filesystem operations. A remote user can perform an operation after another user logs in with the same username and a different credential to disclose and modify data exposed by another backend.
Exploitation requires an auth-proxy deployment that accepts distinct credentials for the same username and maps them to different backend authorities.
Affected software
rclone
How to mitigate CVE-2026-88017
Install security update from vendor's website.
rclone - update to 1.75.1