Remote Code Execution in PhpSpreadsheet Library by PhpOffice
CVE-2026-45034

9.2CRITICAL

Key Information:

Vendor

PHPoffice

Status
PHPspreadsheet
Vendor
CVE Published:
22 June 2026

What is CVE-2026-45034?

The PhpSpreadsheet library, utilized for handling spreadsheet files in PHP, contains a vulnerability that allows an attacker to execute arbitrary code remotely. This occurs due to improper validation of file wrappers, specifically the phar wrapper. When a phar file is opened, it can inadvertently lead to deserialization of attacker-controlled objects, resulting in potential remote code execution in systems using PHP 7.x. In PHP 8.x, the severity is mitigated, but risks remain if specific functions are called. It is crucial to update to version 1.30.5 or later to ensure affected applications are secured against this exploit.

Affected Version(s)

PhpSpreadsheet < 1.30.5

References

https://github.com/PHPOffice/PhpSpreadsheet/security/advi...
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CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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