SSRF in Phpoffice Phpspreadsheet
CVE-2026-34084
PhpSpreadsheet is a library for reading and writing spreadsheet files. In versions 1.30.2 and earlier, 2.0.0 through 2.1.14, 2.2.0 through 2.4.3, 3.3.0 through 3.10.3, and 4.0.0 through 5.5.0, when the filename argument to IOFactory::load() is user-controlled, an attacker can supply a PHP stream wrapper path (such as phar://, ftp://, or ssh2.sftp://) that passes the is_file() check in File::assertFile(). The phar:// wrapper triggers deserialization of the PHAR metadata, which can lead to remote code execution if a suitable gadget chain is available in the application. The ftp:// and ssh2.sftp:// wrappers can be used for server-side request forgery. This issue has been fixed in versions 1.30.3, 2.1.15, 2.4.4, 3.10.4, and 5.6.0.
Vulnerability class: Insecure Deserialization
EPSS: 0.007 (51.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Phpoffice Phpspreadsheet — versions >= 4.0.0, <= 5.5.0, >= 3.3.0, <= 3.10.3, >= 2.2.0, <= 2.4.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34084?
- CVE-2026-34084 is a critical-severity vulnerability in Phpoffice Phpspreadsheet, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-05-05.
- How severe is CVE-2026-34084?
- Critical severity. CVSS v3 base score is 9.8 out of 10.