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Vulnerability record · CVE-2026-40296 · published 6 May 2026

CVE-2026-40296: Phpoffice phpspreadsheet cross-site scripting vulnerability

Phpoffice · Phpspreadsheet

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.

5.4 CVSS 3.1 Medium EPSS 0.25% · top 85.8% CWE-79 · Cross-site scripting
5.4CVSS 3.1 base score
0.25%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-hrmw-qprp-wgmc ExploitMitigationVendor Advisory
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-hrmw-qprp-wgmc ExploitMitigationVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.2CVE-2026-34084Phpoffice phpspreadsheet deserialization of untrusted data vulnerabilityPhpSpreadsheet is a library for reading and writing spreadsheet files. In versions 1.30.2 and earlier, 2.0.0 through 2.1.14, 2.2.0 through 2.4.3, 3.3…EPSS 0.78%8.8CVE-2024-45291Phpoffice phpspreadsheet server-side request forgery (ssrf) vulnerabilityPHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. It's possible for an attacker to construct an XLSX file that links im…EPSS 0.86%8.8CVE-2019-12331Phpoffice phpspreadsheet xml external entity (xxe) vulnerabilityPHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue. The XmlScanner decodes the sheet1.xml from an .xlsx to utf-8 if something else than UTF-8 is …EPSS 1.4%8.8CVE-2018-19277Phpoffice phpspreadsheet xml injection vulnerabilitysecurityScan() in PHPOffice PhpSpreadsheet through 1.5.0 allows a bypass of protection mechanisms for XXE via UTF-7 encoding in a .xlsx fileEPSS 7.8%8.3CVE-2024-56365Phpoffice phpspreadsheet cross-site scripting vulnerabilityPhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 are vulnerable to unauth…EPSS 0.32%8.3CVE-2024-56366Phpoffice phpspreadsheet cross-site scripting vulnerabilityPhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 are vulnerable to unauth…EPSS 0.33%8.3CVE-2024-56409Phpoffice phpspreadsheet cross-site scripting vulnerabilityPhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 are vulnerable to unauth…EPSS 0.33%8.3CVE-2024-56408Phpoffice phpspreadsheet cross-site scripting vulnerabilityPhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 have no sanitization in …EPSS 0.40%

Source: NIST National Vulnerability Database (record CVE-2026-40296), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.