CVE-2026-27954 MEDIUM

CVE-2026-27954: LiveHelperChat has department-level authorization bypass in holdaction, blockuser, and transferchat endpoints

Vendor Livehelperchat
Product livehelperchat
Weakness CWE-862 · Missing authorization
Published February 26, 2026
Last update February 26, 2026

CVSS base score

4.9/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

Live Helper Chat is an open-source application that enables live support websites. In versions up to and including 4.52, three chat action endpoints (holdaction.php, blockuser.php, and transferchat.php) load chat objects by ID without calling `erLhcoreClassChat::hasAccessToRead()`, allowing operators to act on chats in departments they are not assigned to. Operators with the relevant role permissions (holduse, allowblockusers, allowtransfer) can hold, block users from, or transfer chats in departments they are not assigned to. This is a horizontal privilege escalation within one organization. As of time of publication, no known patched versions are available.

Key dates

02Disclosure timeline

February 26, 2026 CVE published
February 26, 2026 Record updated