CVE-2026-40863

Summary

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 Software

VendorProductVersion RangeStatus
PHPOfficePhpSpreadsheet< 1.30.4affected
PHPOfficePhpSpreadsheet>= 2.0.0, < 2.1.16affected
PHPOfficePhpSpreadsheet>= 2.2.0, < 2.4.5affected
PHPOfficePhpSpreadsheet>= 3.3.0, < 3.10.5affected
PHPOfficePhpSpreadsheet>= 4.0.0, < 5.7.0affected

Weaknesses

  • CWE-770: CWE-770: Allocation of Resources Without Limits or Throttling

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References