CVE-2026-77929

High CVSS 8.8

Published 2026-09-18 · last changed 2026-09-18

The fix

We hold no Microsoft remediation data for CVE-2026-77929, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

ClipBucket v5 before 5.5.3-#182 contains a file upload vulnerability that allows authenticated users to achieve remote code execution by uploading a PHP file with valid image magic bytes through the photo upload endpoint. The FileUpload::manageFile() function in fileupload.class.php fails to update the file extension after MIME validation, allowing an attacker-controlled .php extension to persist on disk and execute as PHP via PHP-FPM when the uploaded file is retrieved.

Sources

NVD record for CVE-2026-77929

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H