What is CVE-2023-28434?

CVE-2023-28434 is a high-severity vulnerability in Minio, classified under Improper Privilege Management. CVSS score: 8.8/10. Published 2023-03-22.

How severe is CVE-2023-28434?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2023-28434 known to be exploited?

Yes. CVE-2023-28434 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-09-19), indicating it is being actively exploited. 18 public proof-of-concept repositories are indexed.

Privilege escalation in Minio

CVE-2023-28434

Minio is a Multi-Cloud Object Storage framework. Prior to RELEASE.2023-03-20T20-16-18Z, an attacker can use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket`. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access. This issue has been patched in RELEASE.2023-03-20T20-16-18Z. As a workaround, enable browser API access and turn off `MINIO_BROWSER=off`.

Vulnerability class: Privilege Escalation

Published 2023-03-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.079 (94.7th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.079 · newest: 0.079 · change: 0.000

Affected products

Minio — versions < RELEASE.2023-03-20T20-16-18Z

Weakness classification (CWE)

CWE-269 — Improper Privilege Management

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2023-09-19. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2023-10-10.

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

github.com/minio/minio/security/advisories/GHSA-2pxw-r47w-4p8c (Vendor Advisory)
github.com/minio/minio/pull/16849 (Exploit, Issue Tracking)
github.com/minio/minio/commit/67f4ba154a27a1b06e48bfabda38355a010dfca5 (Patch)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2023-28434?: CVE-2023-28434 is a high-severity vulnerability in Minio, classified under Improper Privilege Management. CVSS score: 8.8/10. Published 2023-03-22.
How severe is CVE-2023-28434?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2023-28434 known to be exploited?: Yes. CVE-2023-28434 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-09-19), indicating it is being actively exploited. 18 public proof-of-concept repositories are indexed.