What is CVE-2026-45034?

CVE-2026-45034 is a vulnerability in Phpoffice Phpspreadsheet, classified under Deserialization of Untrusted Data. Published 2026-06-22.

Is CVE-2026-45034 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Deserialization in Phpoffice Phpspreadsheet

CVE-2026-45034

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. Prior to 1.30.5, CVE-2026-34084 was patched by the helper File::prohibitWrappers. The helper calls parse_url($filename, PHP_URL_SCHEME) and then checks is_stri…

Vulnerability class: Insecure Deserialization

EPSS: 0.004 (27.8th percentile) — read the EPSS interpretation.

Affected products

Phpoffice Phpspreadsheet — versions < 1.30.5

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

Public proof-of-concept exploits

Cyber-DarkNay/CVE-2026-45034

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-45034?: CVE-2026-45034 is a vulnerability in Phpoffice Phpspreadsheet, classified under Deserialization of Untrusted Data. Published 2026-06-22.
Is CVE-2026-45034 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.