How severe is CVE-2026-27954?

CVE-2026-27954 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-27954 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27954?

CVE-2026-27954 affects Livehelperchat Live Helper Chat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27954?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-27954 have an EU (EUVD) identifier?

Yes. CVE-2026-27954 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8815.

When was CVE-2026-27954 published?

CVE-2026-27954 was published on 2026-02-26 and last updated on 2026-06-17.

CVE-2026-27954

CVE-2026-27954 is a medium-severity vulnerability in Livehelperchat Live Helper Chat with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 4.9
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8815
Weakness: CWE-862
Affected product: Livehelperchat Live Helper Chat
Published: 2026-02-26
Last modified: 2026-06-17

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.

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 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-27954 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27954?: CVE-2026-27954 affects Livehelperchat Live Helper Chat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27954?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-27954 have an EU (EUVD) identifier?: Yes. CVE-2026-27954 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8815.
When was CVE-2026-27954 published?: CVE-2026-27954 was published on 2026-02-26 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:livehelperchat:live_helper_chat:*:*:*:*:*:*:*:*

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