RCE in Lagom Whmcs Template
CVE-2026-4239
A vulnerability was found in Lagom WHMCS Template up to 2.3.7. Impacted is an unknown function of the component Datatables. The manipulation results in improperly controlled modification of object prototype attributes. It is possible to launch the attack remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (26.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Lagom Whmcs Template — versions 2.3.0, 2.3.1, 2.3.2
Weakness classification (CWE)
References
- vuldb.com/ (vdb-entry)
- vuldb.com/ (signature, permissions-required)
- vuldb.com/ (third-party-advisory)
- github.com/devsamuelsantiago/lagom-prototype-pollution-poc/ (exploit)
- github.com/devsamuelsantiago/lagom-prototype-pollution-poc/blob/main/lagom-prot… (exploit)
Frequently asked questions
- What is CVE-2026-4239?
- CVE-2026-4239 is a low-severity vulnerability in Lagom Whmcs Template, classified under Code Injection. CVSS score: 3.5/10. Published 2026-03-16.
- How severe is CVE-2026-4239?
- Low severity. CVSS v3 base score is 3.5 out of 10.