---
title: "CVE-2026-88018: rclone - Authentication Bypass"
description: "rclone < 1.75.1 contains an authentication bypass caused by authPairMiddleware registering any client-chosen accessKeyID with an empty secret in s3 serve mode with --auth-proxy but without --auth-key, letting unauthenticated network attackers access backend services, exploit requires no authentication."
url: https://panop.io/threat-heartbeat/CVE-2026-88018/
---

# CVE-2026-88018 rclone - Authentication Bypass

rclone < 1.75.1 contains an authentication bypass caused by authPairMiddleware registering any client-chosen accessKeyID with an empty secret in s3 serve mode with --auth-proxy but without --auth-key, letting unauthenticated network attackers access backend services, exploit requires no authentication.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.51% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-88018)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

10 September 2026

Updated

15 October 2026

Weakness

[CWE-287](https://cwe.mitre.org/data/definitions/287.html)

## Vendor fix

Update to version 1.75.1 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-88018](https://nvd.nist.gov/vuln/detail/CVE-2026-88018)
- [https://github.com/rclone/rclone/security/advisories/GHSA-xwwr-4h3p-r22c](https://github.com/rclone/rclone/security/advisories/GHSA-xwwr-4h3p-r22c)
- [https://github.com/rclone/rclone/commit/90595f34f27f569be6b27c57fe5ab65057d323bd](https://github.com/rclone/rclone/commit/90595f34f27f569be6b27c57fe5ab65057d323bd)
- [https://github.com/rclone/rclone/releases/tag/v1.75.1](https://github.com/rclone/rclone/releases/tag/v1.75.1)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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