{"id":"CVE-2026-97731","state":"PUBLISHED","title":"MinIO through 7aac2a2 does not verify that every x-amz-* header present on a request also appears in the client-supplied X-Amz-SignedHeaders list. extractSignedHeaders() in cmd/sig","description":"MinIO through 7aac2a2 does not verify that every x-amz-* header present on a request also appears in the client-supplied X-Amz-SignedHeaders list. extractSignedHeaders() in cmd/signature-v4-utils.go iterates only the claimed list and never enumerates the headers that actually arrived, and thus a header that arrives unsigned is neither hashed into the canonical request nor rejected. Because cmd/api-router.go dispatches CopyObject on the presence of x-amz-copy-source alone, the holder of a presigned PUT URL scoped to a single object can add that header to the unmodified URL and cause a server-side copy, executed as the signer, of any object the signing key can read. A grant to write one object becomes a read of every bucket that key can reach. Amazon S3 rejects the equivalent request with HTTP 403 AccessDenied. The minio/minio GitHub repository was archived in April 2026; pgsty/silo before 1233254 is also affected.","publishedAt":"2026-09-25T03:07:30.661Z","updatedAt":"2026-09-25T15:22:53.901Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","source":"mitre"},"assigner":"mitre","products":["MinIO MinIO"],"affected":[{"vendor":"MinIO","product":"MinIO","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"7aac2a2c5b7c882e68c1ce017d8256be2feea27f","versionType":"git"}],"repo":"https://github.com/minio/minio"}],"references":["https://silo.pgsty.com/about/security-advisories/#sn-2026-011","https://github.com/pgsty/silo/commit/1233254309b15571f101b2b26d531951ceaeef1e"],"weaknesses":["CWE-347"],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97731.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97731","state":"PUBLISHED","datePublished":"2026-09-25T03:07:30.661Z","dateUpdated":"2026-09-25T15:22:53.901Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-09-25T03:07:29.873Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"MinIO through 7aac2a2 does not verify that every x-amz-* header present on a request also appears in the client-supplied X-Amz-SignedHeaders list. extractSignedHeaders() in cmd/signature-v4-utils.go iterates only the claimed list and never enumerates the headers that actually arrived, and thus a header that arrives unsigned is neither hashed into the canonical request nor rejected. Because cmd/api-router.go dispatches CopyObject on the presence of x-amz-copy-source alone, the holder of a presigned PUT URL scoped to a single object can add that header to the unmodified URL and cause a server-side copy, executed as the signer, of any object the signing key can read. A grant to write one object becomes a read of every bucket that key can reach. Amazon S3 rejects the equivalent request with HTTP 403 AccessDenied. The minio/minio GitHub repository was archived in April 2026; pgsty/silo before 1233254 is also affected."}],"affected":[{"vendor":"MinIO","product":"MinIO","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"7aac2a2c5b7c882e68c1ce017d8256be2feea27f","versionType":"git"}],"repo":"https://github.com/minio/minio"}],"references":[{"url":"https://silo.pgsty.com/about/security-advisories/#sn-2026-011"},{"url":"https://github.com/pgsty/silo/commit/1233254309b15571f101b2b26d531951ceaeef1e"}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","description":"CWE-347 Improper Verification of Cryptographic Signature","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-09-25T03:07:30.661Z"},"x_generator":{"engine":"CVE-Request-form 0.0.1"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:minio:minio:*:*:*:*:*:*:*:*","versionEndIncluding":"7aac2a2c5b7c882e68c1ce017d8256be2feea27f"}]}]}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-25T15:22:42.586752Z","id":"CVE-2026-97731","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-25T15:22:53.901Z"}}]}}}