CVE-2026-40863
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 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.
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Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
phpoffice/phpspreadsheetPackagist | >= 4.0.0, < 5.7.0 | 5.7.0 |
phpoffice/phpspreadsheetPackagist | >= 3.3.0, < 3.10.5 | 3.10.5 |
phpoffice/phpspreadsheetPackagist | >= 2.2.0, < 2.4.5 | 2.4.5 |
phpoffice/phpspreadsheetPackagist | >= 2.0.0, < 2.1.16 | 2.1.16 |
phpoffice/phpspreadsheetPackagist | < 1.30.4 | 1.30.4 |
Affected products
3<= 1.30.3+ 1 more
- (no CPE)range: <= 1.30.3
- cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*range: <1.30.4
Patches
Vulnerability mechanics
References
3- github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6nvdExploitMitigationVendor AdvisoryWEB
- github.com/advisories/GHSA-84wq-86v6-x5j6ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-40863ghsaADVISORY
News mentions
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