Arbitrary file upload in Creative Themes Blocksy Companion
CVE-2026-58480
Blocksy Companion Pro plugin for WordPress before 2.1.47 contains an unauthenticated arbitrary file upload vulnerability that allows attackers to upload executable files by bypassing extension validation in the save_attachments function exposed through the Advanced Reviews feature. Attackers can exploit the Custom Fonts extension's flawed strpos() substring check by uploading double-extension filenames such as shell.woff2.php, causing the validation to pass on the substring match while the web server executes the file as PHP, achieving remote code execution.
Vulnerability class: Unrestricted File Upload
EPSS: 0.019 (78.7th 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
- Creative Themes Blocksy Companion — versions 0, 2.1.47
Weakness classification (CWE)
Public proof-of-concept exploits
References
- disclosure@vulncheck.com (third-party-advisory)
- disclosure@vulncheck.com (third-party-advisory)
- disclosure@vulncheck.com (product, patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-58480?
- CVE-2026-58480 is a critical-severity vulnerability in Creative Themes Blocksy Companion, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2026-07-08.
- How severe is CVE-2026-58480?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-58480 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.