What’s Vulnerable › Vulnerabilities

CVE-2026-71191

• Severity: medium (CVSS 6.0 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-05 · updated 2026-10-24
• Weakness: CWE-863

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.

Affected products

• OpenStack Swift: from 2.18.0 before 2.35.4; from 2.36.0 before 2.36.3; from 2.37.0 before 2.37.3; 2.38.0 — fixed in 2.35.4, 2.36.3, 2.37.3

How to fix

Upgrade to a fixed version: OpenStack Swift 2.35.4, 2.36.3, 2.37.3. Check the vendor advisory for mitigations.

References

• https://launchpad.net/bugs/2158733
• https://openwall.com/lists/oss-security/2026/07/28/26
• https://security.openstack.org/ossa/OSSA-2026-030.html

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