CVE-2026-40902: PhpSpreadsheet: CPU Denial of Service via Unbounded Row Number in XLSX Row Dimensions
PHPOffice · PhpSpreadsheet
Affected: PHPOffice PhpSpreadsheet · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 34% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- PHPOffice · PhpSpreadsheet< 1.30.4; >= 2.0.0, < 2.1.16; >= 2.2.0, < 2.4.5; >= 3.3.0, < 3.10.5; >= 4.0.0, < 5.7.0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
CoverageNo articles yet
No CyberSIXT article names CVE-2026-40902 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.