{"id":"CVE-2026-40863","state":"PUBLISHED","title":"PhpSpreadsheet: CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader","description":"PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0, the SpreadsheetML XML reader (Reader\\Xml) does not validate the ss:Index row attribute against the maximum allowed row count (AddressRange::MAX_ROW = 1,048,576). An attacker can craft a SpreadsheetML XML file with ss:Index=\"999999999\" on a <Row> element, which inflates the internal cachedHighestRow to ~1 billion. Any subsequent call to getRowIterator() without an explicit end row will attempt to iterate ~1 billion rows, causing CPU exhaustion and denial of service. This vulnerability is fixed in 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0.","publishedAt":"2026-05-12T22:04:29.510Z","updatedAt":"2026-05-13T15:03:23.782Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["PHPOffice PhpSpreadsheet"],"affected":[{"vendor":"PHPOffice","product":"PhpSpreadsheet","versions":[{"version":"< 1.30.4","status":"affected"},{"version":">= 2.0.0, < 2.1.16","status":"affected"},{"version":">= 2.2.0, < 2.4.5","status":"affected"},{"version":">= 3.3.0, < 3.10.5","status":"affected"},{"version":">= 4.0.0, < 5.7.0","status":"affected"}]}],"references":["https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40863.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40863","state":"PUBLISHED","datePublished":"2026-05-12T22:04:29.510Z","dateUpdated":"2026-05-13T15:03:23.782Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-15T15:57:41.717Z"},"containers":{"cna":{"title":"PhpSpreadsheet: CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader","descriptions":[{"lang":"en","value":"PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0, the SpreadsheetML XML reader (Reader\\Xml) does not validate the ss:Index row attribute against the maximum allowed row count (AddressRange::MAX_ROW = 1,048,576). An attacker can craft a SpreadsheetML XML file with ss:Index=\"999999999\" on a <Row> element, which inflates the internal cachedHighestRow to ~1 billion. Any subsequent call to getRowIterator() without an explicit end row will attempt to iterate ~1 billion rows, causing CPU exhaustion and denial of service. This vulnerability is fixed in 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0."}],"affected":[{"vendor":"PHPOffice","product":"PhpSpreadsheet","versions":[{"version":"< 1.30.4","status":"affected"},{"version":">= 2.0.0, < 2.1.16","status":"affected"},{"version":">= 2.2.0, < 2.4.5","status":"affected"},{"version":">= 3.3.0, < 3.10.5","status":"affected"},{"version":">= 4.0.0, < 5.7.0","status":"affected"}]}],"references":[{"url":"https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6","name":"https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-12T22:04:29.510Z"},"source":{"advisory":"GHSA-84wq-86v6-x5j6","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-13T15:01:42.488212Z","id":"CVE-2026-40863","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-13T15:03:23.782Z"}}]}}}