CVE-2025-31489

EPSS 1.4%

MinIO performs incomplete signature validation for unsigned-trailer uploads

Published: 4/4/2025Modified: 2/4/2026

Description

### 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`

Affected packages (3)

CVSS scores

SourceVersionSeverityVector
osvCVSS 4.0CVSS: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

References (5)