OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0 S3API Middleware X-Amz-Copy-Source improper authorization

Summaryinfo

A vulnerability has been found in OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0 and classified as critical. This affects an unknown part of the component S3API Middleware. Performing a manipulation of the argument X-Amz-Copy-Source results in improper authorization. This vulnerability is known as CVE-2026-71191. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in OpenStack Swift up to 2.35.3/2.36.2/2.37.2/2.38.0. It has been classified as critical. This affects an unknown part of the component S3API Middleware. The manipulation of the argument X-Amz-Copy-Source with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at launchpad.net. This vulnerability is uniquely identified as CVE-2026-71191 since 08/05/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 2.35.4, 2.36.3 or 2.37.3 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Cloud Software

Vendor

• OpenStack

Name

• Swift

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.35.0
• 2.35.1
• 2.35.2
• 2.35.3
• 2.36
• 2.36.0
• 2.36.1
• 2.36.2
• 2.37
• 2.37.0
• 2.37.1
• 2.37.2
• 2.38.0

License

• free

Website

• Vendor: https://www.openstack.org/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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