How severe is CVE-2017-7739?

CVE-2017-7739 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-2017-7739 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-7739?

CVE-2017-7739 primarily affects Fortinet Fortios. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-7739?

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

When was CVE-2017-7739 published?

CVE-2017-7739 was published on 2017-11-13 and last updated on 2026-06-17.

CVE-2017-7739

CVE-2017-7739 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: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Fortinet Fortios
Published: 2017-11-13
Last modified: 2026-06-17

Description

A reflected Cross-site Scripting (XSS) vulnerability in web proxy disclaimer response web pages in Fortinet FortiOS 5.6.0, 5.4.0 to 5.4.5, 5.2.0 to 5.2.11 allows an unauthenticated attacker to inject arbitrary web script or HTML in the context of the victim's browser via sending a maliciously crafted URL to the victim.

Frequently asked questions

What is CVE-2017-7739?: A reflected Cross-site Scripting (XSS) vulnerability in web proxy disclaimer response web pages in Fortinet FortiOS 5.6.0, 5.4.0 to 5.4.5, 5.2.0 to 5.2.11 allows an unauthenticated attacker to inject arbitrary web script or HTML in the context of the victim's browser via sending a maliciously crafted URL to the victim.
How severe is CVE-2017-7739?: CVE-2017-7739 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-2017-7739 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-7739?: CVE-2017-7739 primarily affects Fortinet Fortios. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-7739?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-7739 published?: CVE-2017-7739 was published on 2017-11-13 and last updated on 2026-06-17.

References

Affected products (19)

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:5.2.3:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.4:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.5:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.6:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.7:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.8:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.9:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.10:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.2.11:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.0:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.1:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.2:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.3:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.4:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.4.5:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:5.6.0:*:*:*:*:*:*:*

More vulnerabilities in Fortinet Fortios

CVE-2005-3057 — Critical (CVSS 10.0): The FTP component in FortiGate 2.8 running FortiOS 2.8MR10 and v3beta, and other versions before 3.0 MR1, allows remote…
CVE-2026-24858 — Critical (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet…
CVE-2025-59718 — Critical (CVSS 9.8): A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0…
CVE-2025-22252 — Critical (CVSS 9.8): A missing authentication for critical function in Fortinet FortiProxy versions 7.6.0 through 7.6.1, FortiSwitchManager…
CVE-2023-25610 — Critical (CVSS 9.8): A buffer underwrite ('buffer underflow') vulnerability in the administrative interface of Fortinet FortiOS version…
CVE-2024-55591 — Critical (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0…

All CVEs affecting Fortinet Fortios →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →