How severe is CVE-2021-43858?

CVE-2021-43858 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43858 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 35% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43858?

CVE-2021-43858 affects Minio. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43858?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-43858 published?

CVE-2021-43858 was published on 2021-12-27 and last updated on 2026-06-17.

CVE-2021-43858

CVE-2021-43858 is a high-severity vulnerability in Minio with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 35% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-863.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 35% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Minio
Published: 2021-12-27
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-43858?: 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.
How severe is CVE-2021-43858?: CVE-2021-43858 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43858 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 35% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43858?: CVE-2021-43858 affects Minio. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43858?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-43858 published?: CVE-2021-43858 was published on 2021-12-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:minio:minio:*:*:*:*:*:*:*:*

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