How severe is CVE-2026-4239?

CVE-2026-4239 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-4239 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-4239?

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

Does CVE-2026-4239 have an EU (EUVD) identifier?

Yes. CVE-2026-4239 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12432.

When was CVE-2026-4239 published?

CVE-2026-4239 was published on 2026-03-16 and last updated on 2026-06-17.

CVE-2026-4239

CVE-2026-4239 is a low-severity vulnerability with a CVSS 3.x base score of 3.5. 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-94.

Key facts

Severity: Low (CVSS 3.x base score 3.5)
CVSS v2: 4.0
CVSS v4: 2.0
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-12432
Weakness: CWE-94
Published: 2026-03-16
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-4239?: CVE-2026-4239 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-4239 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4239?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4239 have an EU (EUVD) identifier?: Yes. CVE-2026-4239 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12432.
When was CVE-2026-4239 published?: CVE-2026-4239 was published on 2026-03-16 and last updated on 2026-06-17.

References

Other CWE-94 (Code Injection) vulnerabilities

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CVE-2026-10561 — Critical (CVSS 10.0): IBM Langflow OSS 1.0.0 through 1.9.3 has an vulnerability due to an improper isolation of Python execution combined…
CVE-2026-25470 — Critical (CVSS 10.0): Improper Control of Generation of Code ('Code Injection') vulnerability in ACPT ACPT (Pro) - Custom Post Types Plugin…
CVE-2026-48836 — Critical (CVSS 10.0): Unauthenticated Remote Code Execution (RCE) in Easy Invoice <= 2.1.19 versions.

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