CVE-2026-40296
Description
PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. The HTML writer skips htmlspecialchars escaping when a cell's formatted value differs from the original value. When a cell has a custom number format containing the text placeholder @ along with any additional literal characters (for example ". @", "@ ", or "x@"), the formatter replaces @ with the cell value and adds the extra characters, causing the formatted value to differ from the original and bypassing HTML escaping entirely. An attacker who can control the cell value and number format of an uploaded spreadsheet that is later converted to HTML and displayed to other users can achieve stored cross-site scripting. This issue is fixed in versions 5.7.0, 3.10.5, 2.4.5, 2.1.16, and 1.30.4.
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Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
phpoffice/phpspreadsheetPackagist | >= 4.0.0, < 5.7.0 | 5.7.0 |
phpoffice/phpspreadsheetPackagist | >= 3.3.0, < 3.10.5 | 3.10.5 |
phpoffice/phpspreadsheetPackagist | >= 2.2.0, < 2.4.5 | 2.4.5 |
phpoffice/phpspreadsheetPackagist | >= 2.0.0, < 2.1.16 | 2.1.16 |
phpoffice/phpspreadsheetPackagist | < 1.30.4 | 1.30.4 |
Affected products
3<= 1.30.3+ 1 more
- (no CPE)range: <= 1.30.3
- cpe:2.3:a:phpoffice:phpspreadsheet:*:*:*:*:*:*:*:*range: <1.30.4
Patches
Vulnerability mechanics
References
3- github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-hrmw-qprp-wgmcnvdExploitMitigationVendor AdvisoryWEB
- github.com/advisories/GHSA-hrmw-qprp-wgmcghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-40296ghsaADVISORY
News mentions
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