CVE-2026-88017: high-severity vulnerability in rclone
rclone: FTP cross-session auth-proxy backend confusion
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.3epss 0.2%
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:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Affected products
rclone · rcloneRelated CVEs — rclone
In the same product, most dangerous first.
CVE-2026-41176CRITICALRclone: Unauthenticated options/set allows runtime auth bypass, leading to sensitive operations and command executionEPSS 32.7%CVE-2026-41179CRITICALRClone: Unauthenticated operations/fsinfo allows attacker-controlled backend instantiation and local command executionEPSS 8.6%CVE-2026-49980CRITICALRclone: Unauthenticated command execution in `rclone rcd --rc-serve` via inline remote instantiation, bypassing CVE-2026-41179 fixEPSS 0.8%CVE-2026-88045HIGHrclone: S3 multipart declared-length memory exhaustionEPSS 0.6%CVE-2026-71310MEDIUMrclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone MemoryEPSS 0.6%CVE-2026-59733HIGHrclone `serve restic --private-repos` authorization bypass: `..` in the URL path lets an authenticated user read, overwrite and delete other users' repositoriesEPSS 0.6%