Cross-Bucket Read Vulnerability in MinIO by MinIO Inc.
CVE-2026-122267

8.8HIGH

Key Information:

Vendor

Chainguard

Status
Minio
Vendor
CVE Published:
5 November 2026

What is CVE-2026-122267?

A vulnerability exists in MinIO that allows the signature V4 verification process to accept unsigned x-amz-* headers. This flaw enables an attacker to escalate a presigned PUT URL into a potential cross-bucket read access, compromising data isolation between different storage buckets. Proper validation measures should be implemented to prevent exploitation.

Affected Version(s)

MinIO 0

References

https://github.com/chainguard-forks/minio/security/adviso...

CVSS V4

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Oren Yomtov of Act Security
.