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CVE-2026-27954

MEDIUMCVSS 4.9/10EPSS 0.19%

Last modified

CVE-2026-27954 is a medium-severity vulnerability rated 4.9/10 on the CVSS scale. 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. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
6.5/10

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

CVSS 4.0
4.9/10

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.19%

8.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LivehelperchatLive Helper Chat<= 4.52

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-27954?
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.
How severe is CVE-2026-27954?
CVE-2026-27954 has a CVSS score of 4.9/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2026-27954?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-27954?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST