CVE-2026-71191
Severity CVSS v4.0:
MEDIUM
Type:
Unavailable / Other
Publication date:
05/08/2026
Last modified:
06/08/2026
Description
In OpenStack Swift through 2.38.0, S3API middleware does not enforce that semantic x-amz-* headers are covered by the SigV4 signature on presigned URL requests. An attacker who obtains a presigned PUT URL can inject an unsigned X-Amz-Copy-Source header, causing Swift to perform a server-side copy from an arbitrary source object using the signer's authorization context. The attacker can read any object the signer has access to, provided the target project_id, container name, and object name are known. This affects all deployments using the default s3_acl=false configuration.
Impact
Base Score 4.0
6.00
Severity 4.0
MEDIUM