{“lastseen”:””,”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 \\u003cRow\\u003e 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.”,”published”:”2026-05-12T22:04:29.510Z”,”modified”:”2026-05-12T22:04:29.510Z”,”type”:”cve”,”title”:”PhpSpreadsheet: CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader”,”source”:”GitHub_M”,”references”:”https:\/\/github.com\/PHPOffice\/PhpSpreadsheet\/security\/advisories\/GHSA-84wq-86v6-x5j6″,”id”:”CVE-2026-40863″,”bulletinFamily”:””,”cwe”:[“CWE-770″],”cvelist”:null,”sourceData”:”PHPOffice PhpSpreadsheet \\u003c 1.30.4\\nPHPOffice PhpSpreadsheet \\u003e= 2.0.0, \\u003c 2.1.16\\nPHPOffice PhpSpreadsheet \\u003e= 2.2.0, \\u003c 2.4.5\\nPHPOffice PhpSpreadsheet \\u003e= 3.3.0, \\u003c 3.10.5\\nPHPOffice PhpSpreadsheet \\u003e= 4.0.0, \\u003c 5.7.0″,”sourceHref”:””,”cvss”:{“score”:7.5,”severity”:”HIGH”,”vector”:”CVSS:3.1\/AV:N\/AC:L\/PR:N\/UI:N\/S:U\/C:N\/I:N\/A:H”,”version”:”3.1″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:””,”category_name”:”CVE”,”post_link”:””,”product”:”PhpSpreadsheet”,”version”:”\\u003c 1.30.4″,”vendor”:”PHPOffice”,”ai_description”:””,”ai_severity”:””,”ai_vendor”:””,”ai_product”:””,”ai_version”:””,”ai_score”:0}<\/p>\n","protected":false},"excerpt":{"rendered":"
{“lastseen”:””,”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)…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[6,8,16,12,15,13,7,11,5],"class_list":["post-53837","post","type-post","status-publish","format-standard","hentry","category-category_cve","tag-cve","tag-cvss","tag-cvss-75","tag-exploit","tag-high","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n