Bug 2536988

Summary: CVE-2026-88017 rclone: rclone: FTP authentication flaw allows unauthorized data access [fedora-all]
Product: [Fedora] Fedora Reporter: Vladimir Vasilev <vvasilev>
Component: rcloneAssignee: Mikel Olasagasti Uranga <mikel>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: go-sig, mikel
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["20de79bb-b6e1-498c-a900-1211d21c47df"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2531540    

Description Vladimir Vasilev 2026-09-18 11:48:07 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.