What’s Vulnerable › Vulnerabilities

CVE-2020-7776: Cross-site Scripting (XSS)

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-12-09 · updated 2026-06-17
• Weakness: CWE-79

Description

This affects the package phpoffice/phpspreadsheet from 0.0.0. The library is vulnerable to XSS when creating an html output from an excel file by adding a comment on any cell. The root cause of this issue is within the HTML writer where user comments are concatenated as part of link and this is returned as HTML. A fix for this issue is available on commit 0ed5b800be2136bcb8fa9c1bdf59abc957a98845/master branch.

Affected products

• PHPOffice PhpSpreadsheet: before 1.16.0 — fixed in 1.16.0

How to fix

Upgrade to a fixed version: PHPOffice PhpSpreadsheet 1.16.0. Check the vendor advisory for mitigations.

References

• https://github.com/PHPOffice/PhpSpreadsheet/blob/master/src/PhpSpreadsheet/Writer/Html.php%23L1792
• https://github.com/PHPOffice/PhpSpreadsheet/commit/0ed5b800be2136bcb8fa9c1bdf59abc957a98845
• https://snyk.io/vuln/SNYK-PHP-PHPOFFICEPHPSPREADSHEET-1048856
• https://github.com/PHPOffice/PhpSpreadsheet/blob/master/src/PhpSpreadsheet/Writer/Html.php%23L1792
• https://github.com/PHPOffice/PhpSpreadsheet/commit/0ed5b800be2136bcb8fa9c1bdf59abc957a98845
• https://snyk.io/vuln/SNYK-PHP-PHPOFFICEPHPSPREADSHEET-1048856

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