MinIO performs incomplete signature validation for unsigned-trailer uploads
HighCVE-2025-31489 · Published Apr 4, 2025 · updated Aug 7, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| github.com/minio/minio Go | < 0.0.0-20250403145552-8c70975283f9 | 0.0.0-20250403145552-8c70975283f9 |
Details and references
### Impact This is a high priority vulnerability and users must upgrade ASAP. The signature component of the authorization may be invalid, which would mean that as a client you can use any arbitrary secret to upload objects given the user already has prior WRITE permissions on the bucket, Prior knowledge of access-key, and bucket name this user might have access to - and an access-key with a WRITE permissions is necessary. However with relevant information in place, uploading random objects to buckets is trivial and easy via `curl` ### Patches Yes https://github.com/minio/minio/pull/21103 ### Workarounds Reject requests with `x-amz-content-sha256: STREAMING-UNSIGNED-PAYLOAD-TRAILER` for now at LB layer, ask application users to use `STREAMING-AWS4-HMAC-SHA256-PAYLOAD-TRAILER`
- CVSS 4.0
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-347
- Also known as
- BIT-minio-2025-31489, CVE-2025-31489, GO-2025-3594
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| Mar 32025 | MinIO allows an SFTP authentication bypass due to improperly trusted SSH key CVE-2025-27414Mediumfixed in 0.0.0-20250227184332-4c71f1b4ec0f | Medium | 0.0.0-20250227184332-4c71f1b4ec0f |
| Dec 162024 | MinIO vulnerable to privilege escalation in IAM import API CVE-2024-55949Highfixed in 0.0.0-20241213221912-68b004a48f41 | High | 0.0.0-20241213221912-68b004a48f41 |
| Oct 162025 | MinIO is Vulnerable to Privilege Escalation via Session Policy Bypass in Service Accounts and STS CVE-2025-62506High8.1fixed in 0.0.0-20251015170045-c1a49490c78e | High8.1 | 0.0.0-20251015170045-c1a49490c78e |
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