9.1
CRITICAL CVSS 3.1
CVE-2026-88044
rclone: RC per-server auth-proxy bypass
Description

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.70.0 until 1.75.1, the serve/start RC interface accepts per-server proxyOpt.AuthProxy settings, and the FTP and S3 constructors in cmd/serve/ftp/ftp.go and cmd/serve/s3/server.go incorrectly check the process-global proxy.Opt.AuthProxy value instead. When the global value is empty, the request-local authentication proxy is ignored: FTP falls back to the fixed filesystem with username anonymous and any password, while S3 with AuthKey serves the fixed RC fs rather than the backend selected by the proxy. The dedicated command-line servers that configure the global option are not affected. This issue is fixed in version 1.75.1.

INFO

Published Date :

Sept. 10, 2026, 5:17 p.m.

Last Modified :

Sept. 10, 2026, 5:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-88044 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Rclone rclone
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update rclone to version 1.75.1 or later to fix incorrect proxy authentication handling.
  • Update rclone to version 1.75.1.
  • Verify proxyOpt.AuthProxy settings are correctly applied.
  • Ensure global proxy.Opt.AuthProxy is properly configured.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-88044.

URL Resource
https://github.com/rclone/rclone/commit/739403963abf6f58003c2becd5f7c4ad0d644153
https://github.com/rclone/rclone/releases/tag/v1.75.1
https://github.com/rclone/rclone/security/advisories/GHSA-p569-5gjg-9cmj
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-88044 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-88044 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-88044 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-88044 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 10, 2026

    Action Type Old Value New Value
    Added Description rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.70.0 until 1.75.1, the serve/start RC interface accepts per-server proxyOpt.AuthProxy settings, and the FTP and S3 constructors in cmd/serve/ftp/ftp.go and cmd/serve/s3/server.go incorrectly check the process-global proxy.Opt.AuthProxy value instead. When the global value is empty, the request-local authentication proxy is ignored: FTP falls back to the fixed filesystem with username anonymous and any password, while S3 with AuthKey serves the fixed RC fs rather than the backend selected by the proxy. The dedicated command-line servers that configure the global option are not affected. This issue is fixed in version 1.75.1.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-863
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/88xxx/CVE-2026-88044.json">CVE-2026-88044</a>
    Added Reference https://github.com/rclone/rclone/commit/739403963abf6f58003c2becd5f7c4ad0d644153
    Added Reference https://github.com/rclone/rclone/releases/tag/v1.75.1
    Added Reference https://github.com/rclone/rclone/security/advisories/GHSA-p569-5gjg-9cmj
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.