Is CVE-2016-8870 in the CISA KEV catalog?

No. CVE-2016-8870 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2016-8870?

CVE-2016-8870 has a CVSS v3 base score of 8.1 (HIGH).

What is the EPSS score for CVE-2016-8870?

CVE-2016-8870 has an EPSS score of 82.09% (100th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2016-8870?

No published fix for CVE-2016-8870 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2016-8870

HIGHEPSS 100th pctl

8.1

CVSS v3

NVD

Description

The register method in the UsersModelRegistration class in controllers/user.php in the Users component in Joomla! before 3.6.4, when registration has been disabled, allows remote attackers to create user accounts by leveraging failure to check the Allow User Registration configuration setting.

CWE-20Improper Input Validation

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

82.09%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

Patch1

github.com

Exploit1

exploit-db.com

Vendor Advisory1

developer.joomla.org

Third-Party Advisory3

Other references3

Related Vulnerabilities

Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-3400	Critical	10.0	100%	KEV + Ransom	-
CVE-2021-45105	Medium	5.9	100%	-	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2018-7600	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2020-3452	High	7.5	100%	KEV	Fix

Embed a live status badge for CVE-2016-8870

Markdown

[![CVE-2016-8870](https://tridentstack.com/cve/badge/CVE-2016-8870.svg)](https://tridentstack.com/cve/CVE-2016-8870)

HTML

<a href="https://tridentstack.com/cve/CVE-2016-8870"><img src="https://tridentstack.com/cve/badge/CVE-2016-8870.svg" alt="CVE-2016-8870"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

See how it works Start freeThis CVE lookup is free and always will be.

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-06.