CVE-2026-25728: ClipBucket v5 Affected by Remote Code Execution via Avatar/Background File Upload Race Condition
ClipBucket v5 is an open source video sharing platform. Prior to 5.5.3 - #40, a Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability exists in ClipBucket's avatar and background image upload functionality. The application moves uploaded files to a web-accessible location before validating them, creating a window where an attacker can execute arbitrary PHP code before the file is deleted. The uploaded file was moved to a web-accessible path via moveuploadedfile(), then validated via ValidateImage(). If validation failed, the file was deleted via @unlink(). This vulnerability is fixed in 5.5.3 - #40.
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Frequently Asked Questions
What is the severity of CVE-2026-25728?
CVE-2026-25728 is classified as a high-severity vulnerability due to its potential for remote code execution.
How do I fix CVE-2026-25728?
To fix CVE-2026-25728, upgrade your ClipBucket installation to version 5.5.3 or later.
What type of vulnerability is CVE-2026-25728?
CVE-2026-25728 is a remote code execution vulnerability caused by a race condition during file uploads.
Which versions of ClipBucket are affected by CVE-2026-25728?
ClipBucket versions prior to 5.5.3 are affected by CVE-2026-25728.
What impact does CVE-2026-25728 have on ClipBucket users?
CVE-2026-25728 allows attackers to execute arbitrary code on the server, potentially compromising the entire system.