CVE-2026-88013: rclone: http backend forwards custom/auth headers to a different host on redirect

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-10 · updated 2026-09-23
Weakness: CWE-200

Description

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.49.0 until 1.75.1, the HTTP backend attaches headers configured through --http-headers or headers= to requests in backend/http/http.go, while its fshttp.NewClient client follows redirects without a backend-specific http.Client.CheckRedirect policy. A configured remote that redirects to another host can therefore cause custom secrets such as X-Api-Key to be resent to that untrusted destination, and a same-host HTTPS-to-HTTP redirect can expose Authorization or Cookie headers in cleartext. Listing, stat, download, mount, and serve operations can trigger the leak during normal use. This issue is fixed in version 1.75.1.

Affected products

rclone: from 1.49.0 before 1.75.1 — fixed in 1.75.1

How to fix

Upgrade to a fixed version: rclone 1.75.1. Check the vendor advisory for mitigations.

References

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