Quick answers
- Is CVE-2026-122267 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-122267 being exploited in the wild.
- How severe is CVE-2026-122267?
- Informational severity, published 5 November 2026.
- Which products and versions are affected?
- Minio before RELEASE.2026-09-22T19-25-18Z.
- Is there a fix for CVE-2026-122267?
- Yes: fixed in RELEASE.2026-09-22T19-25-18Z. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-122267 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-122267?
- Check whether you run Minio at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: RELEASE.2026-09-22T19-25-18Z
Technical details
The vulnerability exists in Signature V4 verification, specifically in the extractSignedHeaders function, which only validates headers listed in the SignedHeaders field and ignores unsigned x-amz-* headers present in the actual request. An attacker can exploit this by appending x-amz-copy-source or other steering headers to a presigned PUT request to bypass intended scope restrictions. The router dispatches PUT requests with x-amz-copy-source to CopyObjectHandler based on the header alone, allowing server-side copy operations as the signing key.
Affected products
- MinIO MinIO before RELEASE.2026-09-22T19-25-18Z
Timeline
- 2026-11-05: disclosed