CVE-2026-25728

Severity CVSS v4.0:

CRITICAL

Type:

Unavailable / Other

Publication date:

10/02/2026

Last modified:

18/02/2026

Description

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&#39;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 move_uploaded_file(), then validated via ValidateImage(). If validation failed, the file was deleted via @unlink(). This vulnerability is fixed in 5.5.3 - #40.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 9.30 CRITICAL
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

9.30

Severity 4.0

CRITICAL

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High