CVE-2026-94368

A flaw was found in the signature verification logic of noobaa-core, the core component of the NooBaa Multicloud Object Gateway. The issue occurs when the service processes S3 presigned URLs using Signature Version 4 (SigV4). Due to improper validation, the service fails to reject requests containing unsigned x-amz- headers, instead simply dropping them from the signature calculation. This allows an attacker who possesses a valid presigned PUT URL to add an unsigned x-amz-copy-source header, effectively converting a simple upload into a CopyObject operation. This can lead to unauthorized access and copying of any data the original signer is permitted to reach across the entire storage system.

  • Published Sep 21, 2026
  • CVSS 7.1 high
  • 0.2% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-94368 at the National Vulnerability Database