What’s Vulnerable › Vulnerabilities

CVE-2019-12331

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2019-11-07 · updated 2026-06-17
• Weakness: CWE-611

Description

PHPOffice 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 declared in the header. This was a security measurement to prevent CVE-2018-19277 but the fix is not sufficient. By double-encoding the the xml payload to utf-7 it is possible to bypass the check for the string ‚<!ENTITY‘ and thus allowing for an xml external entity processing (XXE) attack.

Affected products

• PHPOffice PhpSpreadsheet: before 1.8.0 — fixed in 1.8.0

How to fix

Upgrade to a fixed version: PHPOffice PhpSpreadsheet 1.8.0. Check the vendor advisory for mitigations.

References

• https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.md#180---2019-07-01
• https://herolab.usd.de/security-advisories/usd-2019-0046/
• https://github.com/PHPOffice/PhpSpreadsheet/blob/master/CHANGELOG.md#180---2019-07-01
• https://herolab.usd.de/security-advisories/usd-2019-0046/

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