A AegiFlow
HIGHCVSS 7.5EPSS 0.4%

CVE-2026-40863

CVE-2026-40863 updated by NVD

Published
2026-04-29
Modified
2026-10-28
EPSS percentile
34%
Sources
github-advisory, nvd

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 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 packages

EcosystemPackageAffected versionsFixed versions
Packagistphpoffice/phpspreadsheet—5.7.0, 3.10.5, 2.4.5, 2.1.16, 1.30.6

Remediation: Upgrade to 5.7.0 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.