{"id":"CVE-2026-71191","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-71191","generatedAt":"2026-10-28T01:49:54.419Z","title":"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.","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.","published":"2026-08-05T06:16:40.000Z","lastModified":"2026-10-24T15:10:00.000Z","status":"Awaiting Analysis","sourceIdentifier":"cve@mitre.org","cvss":{"version":"4.0","score":6,"severity":"MEDIUM","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-863"],"affected":[],"epss":{"score":0.00564,"percentile":0.46633,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.56%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://launchpad.net/bugs/2158733","source":"cve@mitre.org"},{"url":"https://openwall.com/lists/oss-security/2026/07/28/26","source":"cve@mitre.org"},{"url":"https://security.openstack.org/ossa/OSSA-2026-030.html","source":"cve@mitre.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-71191","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}