CVE-2026-6601Public exploitNetwork attack vector

Browser crash via repeated DataTables initialization

Published Apr 20, 2026 · Updated Apr 20, 2026

Uncontrolled resource consumption in RS Studio Lagom WHMCS Client Theme 2.4.0 through 2.4.2 allows remote authenticated users to crash browsers. The public proof of concept initializes the page body's DataTable one million times, each time allocating an array of 100 large strings. The artifact requires JavaScript execution in an affected page's browser and does not demonstrate how a remote authenticated user obtains that execution path.

CVSS severity4.3
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in RS Studio Lagom WHMCS Client Theme 2.4.0 through 2.4.2 allows remote authenticated users to crash browsers. The public proof of concept initializes the page body's DataTable one million times, each time allocating an array of 100 large strings. The artifact requires JavaScript execution in an affected page's browser and does not demonstrate how a remote authenticated user obtains that execution path.

The record

CVE
CVE-2026-6601
Published
Apr 20, 2026
Updated
Apr 20, 2026
Vendor
RS Studio
Product
Lagom WHMCS Client Theme
Classifications
CWE-404, CWE-400, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.4.0
  2. Affected versionversion=2.4.1
  3. Affected versionversion=2.4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

RS Studio · Lagom WHMCS Client Themeversion=2.4.0; version=2.4.1; version=2.4.2

Published CVSS scores

4.0VulDBAV:N/AC:L/Au:S/C:N/I:N/A:P
2.1VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
4.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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