Arbitrary file upload in Prosolution Wp Client

CVE-2026-6555

The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 2.0.0. This is due to an array validation mismatch where only the first file in the upload array undergoes extension and MIME type validation, while all files are processed and uploaded to a web-accessible directory. This makes it possible for unauthenticated attackers to upload malicious PHP files and achieve remote code execution by sending a valid first file followed by a malicious file.

Vulnerability class: Unrestricted File Upload

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.014 (70.4th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6555: held from 0.010 to 0.014.

EPSS over last 30 days · oldest: 0.010 · newest: 0.014 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6555?
CVE-2026-6555 is a critical-severity vulnerability in Prosolution Wp Client, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2026-05-20.
How severe is CVE-2026-6555?
Critical severity. CVSS v3 base score is 9.8 out of 10.