How severe is CVE-2016-9836?

CVE-2016-9836 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-9836 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-9836?

CVE-2016-9836 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-9836?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2016-9836 published?

CVE-2016-9836 was published on 2016-12-05 and last updated on 2026-06-17.

CVE-2016-9836

CVE-2016-9836 is a critical-severity vulnerability in Joomla Joomla! with a CVSS 3.x base score of 9.8. 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-284.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Joomla Joomla!
Published: 2016-12-05
Last modified: 2026-06-17

Description

The file scanning mechanism of JFilterInput::isFileSafe() in Joomla! CMS before 3.6.5 does not consider alternative PHP file extensions when checking uploaded files for PHP content, which enables a user to upload and execute files with the `.php6`, `.php7`, `.phtml`, and `.phpt` extensions. Additionally, JHelperMedia::canUpload() did not blacklist these file extensions as uploadable file types.

Frequently asked questions

What is CVE-2016-9836?: The file scanning mechanism of JFilterInput::isFileSafe() in Joomla! CMS before 3.6.5 does not consider alternative PHP file extensions when checking uploaded files for PHP content, which enables a user to upload and execute files with the `.php6`, `.php7`, `.phtml`, and `.phpt` extensions. Additionally, JHelperMedia::canUpload() did not blacklist these file extensions as uploadable file types.
How severe is CVE-2016-9836?: CVE-2016-9836 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-9836 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-9836?: CVE-2016-9836 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-9836?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2016-9836 published?: CVE-2016-9836 was published on 2016-12-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:joomla:joomla\!:*:*:*:*:*:*:*:*

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