High 8.8Published Oct 22, 2026

CVE-2026-108357PhpSpreadsheet: XmlScanner Bypass via Double-Encoded unentity() TOCTOU Allows XXE and Denial of Service

Updated under an hour ago (Oct 28, 2026, 5:40 AM ET)

Does this affect you?

It affects PHPOffice PhpSpreadsheet. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.36%, higher than 29% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for PHPOffice PhpSpreadsheet

Exploited in the last 30 days

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. From 3.3.0 until 3.10.8 and 5.10.0, Reader\Xml passes stored SpreadsheetML XML through XmlScanner::scan in Xml::canRead and Xml::trySimpleXMLLoadStringPrivate, while Xml::unentity decodes numeric entities only after each DOCTYPE pattern check. A double-encoded less-than character is reduced by the first callback to another encoded character and by the second callback to a literal less-than sign, so SimpleXML receives an unchecked DOCTYPE and entity declaration. Processing attacker-controlled SpreadsheetML XML can cause entity-expansion denial of service and can permit local file access or SSRF on PHP before 8.0 or when LIBXML_NOENT is enabled. This issue is fixed in versions 3.10.8 and 5.10.0.

CVSS: 8.8 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:L/SI:N/SA:N
Weakness (CWE): CWE-611, CWE-776
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.36% (percentile 29)
Assigned by: GitHub_M
NVD analysis: Awaiting Analysis
Record last updated: Oct 23, 2026
First seen by InfoSec Signals: Oct 22, 2026

Affected products

Affected products

PHPOffice PhpSpreadsheet phpoffice:phpspreadsheet (from the name)	from 3.3.0, < 3.10.8; from 4.0.0, < 5.10.0	CNA record

References

References

https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-rxj4-h86g-25gc	x-refsource-confirm
https://github.com/PHPOffice/PhpSpreadsheet/commit/89f455c133e1a7e2d4abfadc43ce29eb7450d781	x-refsource-misc
https://github.com/PHPOffice/PhpSpreadsheet/commit/980b5c294493856f1a25754f1e8a1d2185b93738	x-refsource-misc
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.8	x-refsource-misc
https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.10.0	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.