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

high Affects phpoffice/phpspreadsheet. Feed 2026.10.29.1, updated 2026-10-28; published 2026-10-27.

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

Package: phpoffice/phpspreadsheet Composer
Affected versions: >=4.0.0 and <5.10.0 or >=3.3.0 and <3.10.8
Fixed in: 5.10.0, 3.10.8
Severity: high
Exploitation: not on CISA KEV · EPSS 0% (29.4th percentile)
Published: 2026-10-27
Source: osv.dev

References

NVD record phpoffice/phpspreadsheet advisories

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