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Fencer Vulns
high 7.3

CVE-2026-88017 json

rclone: FTP cross-session auth-proxy backend confusion

published 2026-09-10 59 d ago modified 2026-09-17 52 d ago also BIT-rclone-2026-88017 , EUVD-2026-75577 , GHSA-c476-6w5q-jw77 , GO-2026-6458

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/rclone/rclone 1.75.1
  • bitnami rclone 1.75.1
  • rclone rclone 1.75.1
  • govulncheck-vulndb SLES 16.0, SLES for SAP applications 16.0 0.0.20260916T180043-160000.1.1

suse advisories SUSE-SU-2026:23855-1SUSE-SU-2026:23863-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260916T180043-160000.1.1

opensuse advisories openSUSE-SU-2026:21897-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-88017 updated cvss 9.0

rclone: rclone: FTP authentication flaw allows unauthorized data access

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
58 d ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
GitHub 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
OSV 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/rclone/rclone
>=1.64.0, <1.75.1
1.75.1
bitnami rclone
>=1.64.0, <1.75.1
1.75.1

Affected products

  • rclone rclone

Classification

Weakness
  • CWE-488 Exposure of Data Element to Wrong Session

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.