CVE-2021-43858
User privilege escalation in MinIO
MinIO is a Kubernetes native application for cloud storage. Prior to version RELEASE.2021-12-27T07-23-18Z, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version RELEASE.2021-12-27T07-23-18Z changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit Deny rule to disable the API for users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
User privilege escalation in MinIO
MinIO is a Kubernetes native application for cloud storage. Prior to version RELEASE.2021-12-27T07-23-18Z, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version RELEASE.2021-12-27T07-23-18Z changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit Deny rule to disable the API for users.
- Record
CVE-2021-43858- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-269
- Updated
- 2026-11-02
EUVDEUVD-2021-30723
MinIO is a Kubernetes native application for cloud storage. Prior to version RELEASE.2021-12-27T07-23-18Z, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version RELEASE.2021-12-27T07-23-18Z changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit Deny rule to disable the API for users.
- Record
EUVD-2021-30723- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
NVD
MinIO is a Kubernetes native application for cloud storage. Prior to version RELEASE.2021-12-27T07-23-18Z, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version RELEASE.2021-12-27T07-23-18Z changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit Deny rule to disable the API for users.
- Record
CVE-2021-43858- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-269, CWE-863
- Updated
- 2026-11-02
OSV
MinIO is a Kubernetes native application for cloud storage. Prior to version RELEASE.2021-12-27T07-23-18Z, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version RELEASE.2021-12-27T07-23-18Z changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit Deny rule to disable the API for users.
- Record
CVE-2021-43858- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | 0rx1/cve-2021-43858 | 2022-01-03 |
| PoC in GitHub | khuntor/CVE-2021-43858-MinIO | 2023-04-12 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43858 is a high vulnerability (CVSS 8.8) in Minio, published December 27, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 35.5%, the 98th percentile. No source names a fixed version.