SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-26103

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,…

HIGH 8.8EPSS 0.44%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.44% probability · 38th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-345
Affected
fortinet/fortiproxy · fortinet/fortios
Source
psirt@fortinet.com
EPSS trend
0%3%5%26 October 2026: 0.44%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.