CVE-2026-71191
MEDIUM
MEDIUM
Priority: 0.03
BB Relevance:
62/100
Published: 2026-08-05
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Interaction
Conf. Impact
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
None
S:
X
AT:
Present
VC:
High
VI:
None
VA:
None
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.