CVE-2026-71191

openstack-swift: openstack-swift: S3API presigned URL unsigned header authorization bypass

Published Aug 5, 2026 CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4801-1 swift security update
Debian DSA Debian DSA DSA-6449-1 swift security update
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Unsigned X-Amz-Copy-Source Header Injection in OpenStack Swift S3API Presigned URLs openstack-swift: openstack-swift: S3API presigned URL unsigned header authorization bypass
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N'}

threat_severity

Important

Type Values Removed Values Added
Title Unsigned X-Amz-Copy-Source Header Injection in OpenStack Swift S3API Presigned URLs
Type Values Removed Values Added
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.
First Time appeared Openstack
Openstack swift
Weaknesses CWE-863
CPEs cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
Vendors & Products Openstack
Openstack swift
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 6, 2026, 1:10 PM
Reserved
Aug 5, 2026, 5:01 AM
Status
Awaiting Analysis
Published
Aug 5, 2026, 6:16 AM
Modified
Oct 24, 2026, 3:10 PM
Severity
Important
Public date
Jul 28, 2026, 3:00 PM