CVE-2026-40902

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 XLSX reader's ColumnAndRowAttributes::readRowAttributes() method reads row numbers from XML attributes without validating them against the spreadsheet maximum row limit (AddressRange::MAX_ROW = 1,048,576). An attacker can craft a minimal XLSX file (~1.6KB) containing a <row r="999999999"/> element that inflates cachedHighestRow to 999,999,999, causing any subsequent row iteration to attempt ~1 billion loop cycles and exhaust CPU resources. This vulnerability is fixed in 1.30.4, 2.1.16, 2.4.5, 3.10.5, and 5.7.0.

• phpoffice phpspreadsheet (< 1.30.4) • phpoffice phpspreadsheet (>= 2.0.0 < 2.1.16) • phpoffice phpspreadsheet (>= 2.2.0 < 2.4.5) • phpoffice phpspreadsheet (>= 3.3.0 < 3.10.5) • phpoffice phpspreadsheet (>= 4.0.0 < 5.7.0)