{"id":"CVE-2026-71191","title":"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","summary":"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-Cop…","severity":"none","cwe":["CWE-863"],"published":"2026-08-05","updated":"2026-09-09","sourceUpdated":"2026-09-09T16:03:22.897","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-71191","references":[{"url":"https://launchpad.net/bugs/2158733","label":"cve@mitre.org"},{"url":"https://openwall.com/lists/oss-security/2026/07/28/26","label":"cve@mitre.org"},{"url":"https://security.openstack.org/ossa/OSSA-2026-030.html","label":"cve@mitre.org"}],"tags":["nvd"],"epss":0.00284,"epssPercentile":0.21164,"ingestedAt":"2026-09-09T16:14:05.512Z","slug":"CVE-2026-71191","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}