CVE-2026-88018

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, rclone serve s3 configured with --auth-proxy but without --auth-key allows authPairMiddleware to register any client-chosen accessKeyID with an empty ws.s3Secret. gofakes3 then verifies the request’s SigV4 signature against that same empty secret, while Server.auth passes the access key identifier as both the user and authentication value to the proxy without an independent per-identity secret. An unauthenticated network attacker can therefore choose an arbitrary access key, sign with an empty secret, and reach whatever backend the auth-proxy script resolves for that identity. This issue is fixed in version 1.75.1.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/rclone/rclone/commit/90595f34f27f569be6b27c57fe5ab65057d323bd	Patch
https://github.com/rclone/rclone/releases/tag/v1.75.1	Release Notes
https://github.com/rclone/rclone/security/advisories/GHSA-xwwr-4h3p-r22c	Vendor Advisory
https://github.com/rclone/rclone/security/advisories/GHSA-xwwr-4h3p-r22c	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:rclone:rclone:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-09-10 16:18

Updated : 2026-09-14 20:01

NVD link : CVE-2026-88018

Mitre link : CVE-2026-88018

CVE.ORG link : CVE-2026-88018

JSON object : View

Products Affected

rclone

rclone

CWE

CWE-287

Improper Authentication

CWE-306

Missing Authentication for Critical Function

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