CVE-2026-108359 PhpSpreadsheet ODS Reader: Unbounded number-rows-repeated → CPU & Memory Exhaustion (DoS)

What is CVE-2026-108359?

CVE-2026-108359 is a high-severity vulnerability in PHPOffice PhpSpreadsheet, published on 22 Oct 2026.

Official description

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0, Ods::processTableRow in src/PhpSpreadsheet/Reader/Ods.php accepts an unbounded table:number-rows-repeated attribute from an ODS table row. When the row contains a value, the reader materializes a cell for every repetition without checking the spreadsheet row limit, so a small attacker-controlled ODS file can consume substantial CPU and memory and terminate the PHP worker. Column repetition is separately bounded and is not part of this vulnerability. This issue is fixed in versions 1.30.7, 2.1.19, 2.4.8, 3.10.8, and 5.10.0.

Weakness: CWE-789, CWE-400

Which versions are affected by CVE-2026-108359?

10 open source packages ship an affected version, including phpoffice/phpspreadsheet.

How do I fix CVE-2026-108359?

Upgrade phpoffice/phpspreadsheet to a fixed version for your release line: 1.30.7, 2.1.19, 2.4.8 or 3.10.8.

Is CVE-2026-108359 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108359 exists.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-j2w7-387v-m2rq.