CVE-2019-12331
CVSS v3
8.8
HIGH
EPSS Score
1.4 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- Published
- 2019-11-07
Frequently asked questions
What is CVE-2019-12331?
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.
Is CVE-2019-12331 actively exploited?
Active exploitation of CVE-2019-12331 has not been confirmed. Its EPSS score was 1.4% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2019-12331?
CVE-2019-12331 has a CVSS v3 base score of 8.8 (HIGH severity).
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