CVE-2026-27954
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedLive 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceLive Helper Chat versions up to 4.52 have a horizontal privilege escalation. Three endpoints (holdaction.php, blockuser.php, transferchat.php) load chat objects by ID without verifying operator access via erLhcoreClassChat::hasAccessToRead(), allowing operators to hold, block, or transfer chats in departments they are not assigned to despite having role permissions (holduse, allowblockusers, allowtransfer).
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 4.52CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed Live Helper Chat versionLocate the version file or check the admin dashboard for the current version number. Common locations include a version.php file or the installation's about/admin panel.Affected if The installed version is 4.52 or any earlier version (any version up to and including 4.52).
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Determine if operator roles include the vulnerable permissionsReview the role permission configuration for operators in the admin panel or database. Look for permissions named 'holduse', 'allowblockusers', and 'allowtransfer'.Affected if Any operator role has one or more of these permissions (holduse, allowblockusers, allowtransfer) granted.
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Check if operators are assigned to specific departmentsReview the department assignment configuration for operators. Determine if operators with the above permissions are restricted to specific departments or have access to all departments.Affected if Operators with these permissions are NOT restricted to specific departments (they have access to all chats).
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Verify the vulnerable endpoints existCheck for the presence of holdaction.php, blockuser.php, and transferchat.php in the web-facing directory (typically in the 'extension' or 'modules' folder of the Live Helper Chat installation).Affected if These three endpoint files exist and are accessible on the server.
You are affected if your Live Helper Chat version is 4.52 or earlier AND operators have any of the holduse/allowblockusers/allowtransfer permissions AND those operators can access chats outside their assigned departments.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataAdd erLhcoreClassChat::hasAccessToRead() validation before performing actions in all three vulnerable endpoints. Until official patch is available, consider restricting operator role permissions or implementing compensating network-level access controls.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-27954 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-27954 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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