How severe is CVE-2016-4066?

CVE-2016-4066 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-4066 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4066?

CVE-2016-4066 affects Fortinet Fortiweb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-4066?

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

When was CVE-2016-4066 published?

CVE-2016-4066 was published on 2016-07-13 and last updated on 2026-06-17.

CVE-2016-4066

CVE-2016-4066 is a high-severity vulnerability in Fortinet Fortiweb with a CVSS 3.x base score of 8.8. 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-352.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-352
Affected product: Fortinet Fortiweb
Published: 2016-07-13
Last modified: 2026-06-17

Description

Cross-site request forgery (CSRF) vulnerability in Fortinet FortiWeb before 5.5.3 allows remote attackers to hijack the authentication of administrators for requests that change the password via unspecified vectors.

Frequently asked questions

What is CVE-2016-4066?: Cross-site request forgery (CSRF) vulnerability in Fortinet FortiWeb before 5.5.3 allows remote attackers to hijack the authentication of administrators for requests that change the password via unspecified vectors.
How severe is CVE-2016-4066?: CVE-2016-4066 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-4066 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-4066?: CVE-2016-4066 affects Fortinet Fortiweb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-4066?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-4066 published?: CVE-2016-4066 was published on 2016-07-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*

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