CVE-2021-21362: MinIO

Medium severity, CVSS 6.5. EPSS: 1.3% chance of exploitation in the next 30 days.

MinIO is an open-source high performance object storage service and it is API compatible with Amazon S3 cloud storage service. In MinIO before version RELEASE.2021-03-04T00-53-13Z it is possible to bypass a readOnly policy by creating a temporary 'mc share upload' URL. Everyone is impacted who uses MinIO multi-users. This is fixed in version RELEASE.2021-03-04T00-53-13Z. As a workaround, one can disable uploads with `Content-Type: multipart/form-data` as mentioned in the S3 API RESTObjectPOST docs by using a proxy in front of MinIO.

Affected products

• MinIO MinIO: before 2021-03-04t00-53-13z (fixed in 2021-03-04t00-53-13z)

Published 2021-03-08. Last modified 2026-06-17.