{"id":"CVE-2026-27607","state":"PUBLISHED","title":"RustFS's Missing Post Policy Validation leads to Arbitrary Object Write","description":"RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.56 through 1.0.0-alpha.82, RustFS does not validate policy conditions in presigned POST uploads (PostObject), allowing attackers to bypass content-length-range, starts-with, and Content-Type constraints. This enables unauthorized file uploads exceeding size limits, uploads to arbitrary object keys, and content-type spoofing, potentially leading to storage exhaustion, unauthorized data access, and security bypasses. Version 1.0.0-alpha.83 fixes the issue.","publishedAt":"2026-02-25T02:10:28.086Z","updatedAt":"2026-02-25T20:06:03.487Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["rustfs rustfs"],"affected":[{"vendor":"rustfs","product":"rustfs","versions":[{"version":">= 1.0.0-alpha.56, < 1.0.0-alpha.83","status":"affected"}]}],"references":["https://github.com/rustfs/rustfs/security/advisories/GHSA-w5fh-f8xh-5x3p"],"weaknesses":["CWE-20","CWE-863"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27607.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27607","state":"PUBLISHED","datePublished":"2026-02-25T02:10:28.086Z","dateUpdated":"2026-02-25T20:06:03.487Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-20T19:43:14.602Z"},"containers":{"cna":{"title":"RustFS's Missing Post Policy Validation leads to Arbitrary Object Write","descriptions":[{"lang":"en","value":"RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.56 through 1.0.0-alpha.82, RustFS does not validate policy conditions in presigned POST uploads (PostObject), allowing attackers to bypass content-length-range, starts-with, and Content-Type constraints. This enables unauthorized file uploads exceeding size limits, uploads to arbitrary object keys, and content-type spoofing, potentially leading to storage exhaustion, unauthorized data access, and security bypasses. Version 1.0.0-alpha.83 fixes the issue."}],"affected":[{"vendor":"rustfs","product":"rustfs","versions":[{"version":">= 1.0.0-alpha.56, < 1.0.0-alpha.83","status":"affected"}]}],"references":[{"url":"https://github.com/rustfs/rustfs/security/advisories/GHSA-w5fh-f8xh-5x3p","name":"https://github.com/rustfs/rustfs/security/advisories/GHSA-w5fh-f8xh-5x3p","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-25T02:10:28.086Z"},"source":{"advisory":"GHSA-w5fh-f8xh-5x3p","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-25T20:05:51.123736Z","id":"CVE-2026-27607","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-02-25T20:06:03.487Z"}}]}}}