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

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.

Published Feb 26, 2026Updated Feb 26, 2026Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

livehelperchat

CVSS base

4.9

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

livehelperchat

Products (1)

livehelperchat

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
4.9	CVSS 4.0	MEDIUM	—	—	cvelistV5

Weakness & attack patterns

CWE-862

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

T1211Exploitation for Defensive Evasion
T1542.002Pre-OS Boot: Component Firmware
T1556Modify Authentication Process

References

1 on the record

github.com/LiveHelperChat/livehelperchat/security/advisories/GHSA-87wc-2p86-h3w7
x_refsource_CONFIRM

Elsewhere on this site

livehelperchatevery CVE for this vendor
CWE-862other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.