CVE-2026-40863

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6	Exploit Mitigation Vendor Advisory
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-84wq-86v6-x5j6	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:phpoffice:phpspreadsheet::::::::
	cpe:2.3:a:phpoffice:phpspreadsheet::::::::
	cpe:2.3:a:phpoffice:phpspreadsheet::::::::
	cpe:2.3:a:phpoffice:phpspreadsheet::::::::
	cpe:2.3:a:phpoffice:phpspreadsheet::::::::

History

No history.

Information

Published : 2026-05-12 22:16

Updated : 2026-06-17 10:45

NVD link : CVE-2026-40863

Mitre link : CVE-2026-40863

CVE.ORG link : CVE-2026-40863

JSON object : View

Products Affected

phpoffice

phpspreadsheet

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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