Auth bypass in Rclone

CVE-2026-41176

Rclone is a command-line program to sync files and directories to and from different cloud storage providers. The RC endpoint `options/set` is exposed without `AuthRequired: true`, but it can mutate global runtime configuration, including the RC option block itself. Starting in version 1.45.0 and prior to version 1.73.5, an unauthenticated attacker can set `rc.NoAuth=true`, which disables the authorization gate for many RC methods registered with `AuthRequired: true` on reachable RC servers that are started without global HTTP authentication. This can lead to unauthorized access to sensitive administrative functionality, including configuration and operational RC methods. Version 1.73.5 patches the issue.

Vulnerability class: Broken Authentication

EPSS: 0.327 (98.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Rclone — versions >= 1.45.0, < 1.73.5

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41176?
CVE-2026-41176 is a critical-severity vulnerability in Rclone, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-04-23.
How severe is CVE-2026-41176?
Critical severity. CVSS v3 base score is 9.8 out of 10.