BIT-rclone-2026-116187: Rclone v1.68.0 before v1.75.2 Authorization Bypass in serve s3 Multipart Uploads

Q: Which deployments are exposed to this issue?

Rclone deployments running versions from 1.68.0 before 1.75.2 are affected when using the serve s3 --auth-proxy configuration. The issue concerns multipart-upload operations in multi-tenant environments.

Q: What does an attacker need to exploit the bypass?

The attacker must be an authenticated tenant and must know the victim's bucket, object, and multipart upload ID. Exploitation is not described as requiring user interaction.

Q: What could an attacker do with a victim's upload ID?

An attacker can inject parts into, complete, or abort another tenant's in-progress multipart upload. They can also view multipart-upload and object metadata across tenant boundaries.

Q: What should be done if an affected deployment cannot be patched immediately?

The provided information does not specify a workaround. Until an update is applied, treat multipart upload IDs, bucket names, and object names as sensitive and restrict access to authenticated tenants only as appropriate for the deployment.

Published Oct 25, 2026

Updated

Rclone from v1.68.0 before v1.75.2 contains an authorization bypass vulnerability in serve s3 --auth-proxy that allows authenticated tenants to manipulate other tenants' multipart uploads by referencing their upload IDs. Attackers who learn a victim's bucket, object, and upload ID can inject parts, complete, or abort in-flight uploads and view upload and object metadata across tenants.

Affected Software

1 affected componentFixes available

bitnami/rclone>=1.68.0<1.75.2

1.75.2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade bitnami/rclone to a version that resolves this vulnerability.
Fixed in 1.75.2

Event History

Oct 25, 2026

CVE Published

via OSV·01:20 PM

Data Sourced

via OSV·01:20 PM

DescriptionSeverityWeakness

Oct 29, 2026

Advisory Published

via OSV·08:58 AM

Data Sourced

via OSV·08:58 AM

Affected Software

Frequently Asked Questions

Which deployments are exposed to this issue?

Rclone deployments running versions from 1.68.0 before 1.75.2 are affected when using the serve s3 --auth-proxy configuration. The issue concerns multipart-upload operations in multi-tenant environments.

What does an attacker need to exploit the bypass?

The attacker must be an authenticated tenant and must know the victim's bucket, object, and multipart upload ID. Exploitation is not described as requiring user interaction.

What could an attacker do with a victim's upload ID?

An attacker can inject parts into, complete, or abort another tenant's in-progress multipart upload. They can also view multipart-upload and object metadata across tenant boundaries.

What should be done if an affected deployment cannot be patched immediately?

The provided information does not specify a workaround. Until an update is applied, treat multipart upload IDs, bucket names, and object names as sensitive and restrict access to authenticated tenants only as appropriate for the deployment.

BIT-rclone-2026-116187: Rclone v1.68.0 before v1.75.2 Authorization Bypass in serve s3 Multipart Uploads

Affected Software

Remediation

Event History

Frequently Asked Questions

Which deployments are exposed to this issue?

What does an attacker need to exploit the bypass?

What could an attacker do with a victim's upload ID?

What should be done if an affected deployment cannot be patched immediately?

Company

Resources

Contact

Frequently Asked Questions

Which deployments are exposed to this issue?

What does an attacker need to exploit the bypass?

What could an attacker do with a victim's upload ID?

What should be done if an affected deployment cannot be patched immediately?