CVE-2026-40902

PhpSpreadsheet: CPU Denial of Service via Unbounded Row Number in XLSX Row Dimensions

Published May 12, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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 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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-7c6m-4442-2x6m PhpSpreadsheet has CPU Denial of Service via Unbounded Row Number in XLSX Row Dimensions
History
Type Values Removed Values Added
CPEs cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Phpoffice
Phpoffice phpspreadsheet
Vendors & Products Phpoffice
Phpoffice phpspreadsheet
Type Values Removed Values Added
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 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.
Title PhpSpreadsheet: CPU Denial of Service via Unbounded Row Number in XLSX Row Dimensions
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 13, 2026, 12:11 PM
Reserved
Apr 15, 2026, 4:37 PM
Status
Analyzed
Published
May 12, 2026, 10:16 PM
Modified
Oct 26, 2026, 2:10 PM