How severe is CVE-2016-3978?

CVE-2016-3978 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2016-3978 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-3978?

CVE-2016-3978 primarily affects Fortinet Fortios. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-3978?

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

When was CVE-2016-3978 published?

CVE-2016-3978 was published on 2016-04-08 and last updated on 2026-06-17.

CVE-2016-3978

CVE-2016-3978 is a medium-severity vulnerability in Fortinet Fortios with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 7% (93rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Fortinet Fortios
Published: 2016-04-08
Last modified: 2026-06-17

Description

The Web User Interface (WebUI) in FortiOS 5.0.x before 5.0.13, 5.2.x before 5.2.3, and 5.4.x before 5.4.0 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks or cross-site scripting (XSS) attacks via the "redirect" parameter to "login."

Frequently asked questions

What is CVE-2016-3978?: The Web User Interface (WebUI) in FortiOS 5.0.x before 5.0.13, 5.2.x before 5.2.3, and 5.4.x before 5.4.0 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks or cross-site scripting (XSS) attacks via the "redirect" parameter to "login."
How severe is CVE-2016-3978?: CVE-2016-3978 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2016-3978 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-3978?: CVE-2016-3978 primarily affects Fortinet Fortios. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-3978?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-3978 published?: CVE-2016-3978 was published on 2016-04-08 and last updated on 2026-06-17.

References

Affected products (17)

cpe:2.3:o:fortinet:fortios:5.0.0:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.1:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.2:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.3:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.4:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.5:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.6:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.7:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.8:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.9:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.10:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.11:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.0.12:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.0:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.1:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.2:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4:*:*:*:*:*:*:*

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