Is CVE-2021-26103 being actively exploited?

CVE-2021-26103 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2021-26103?

CVE-2021-26103 has a CVSS 3.1 base score of 6.3 (MEDIUM).

CVE-2021-26103

MEDIUM · CVSS 6.3EPSS 0.4%EU EUVD

An insufficient verification of data authenticity vulnerability (CWE-345) in the user interface of FortiProxy verison 2.0.3 and below, 1.2.11 and below and FortiGate verison 7.0.0, 6.4.6 and below, 6.2.9 and below of SSL VPN portal may allow a remote, unauthenticated attacker to conduct a cross-site request forgery (CSRF) attack . Only SSL VPN in web mode or full mode are impacted by this vulnerability.

Key facts

CVSS score: 6.3 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
Weakness (CWE): CWE-345
EPSS score: 0.4% (36th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-12924)
Published: December 8, 2021
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-12924 in the EU Vulnerability Database. Last updated in EUVD on October 25, 2024.

View on the EU Vulnerability Database

Affected products

fortinet / fortios
fortinet / fortios
fortinet / fortiproxy

Certified products that may be affected

2 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

FortiGate/FortiOS Version 6.2.7 - Fortinet, Inc. - Common Criteria 559-LSS - archived
FortiOS 5.6 - Fortinet, Inc. - FIPS 140 3639 - historical

References

https://fortiguard.com/advisory/FG-IR-20-158(Patch, Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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