Fortinet PSIRT AdvisoriesFG-IR-26-174

ZTNA Portal Improper Certificate Validation

CVSSv3 Score: 7.3 An improper certificate validation vulnerability [CWE-295] in FortiOS and FortiProxy Agentless ZTNA portal may allow a remote and unauthenticated attacker to perform a Man-in-the-Middle attack on the communication channel between the ZTNA portal and the backend destination website. Revised on 2026-09-08 00:00:00

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7.3CVSS out of 10High severity

Scope

What the vendor says is affected

FortiOS
FortiProxy

Timeline

When this advisory changed

Sep 8, 2026 at 7:00 AM UTC
Published by Fortinet
The publication date reported by the vendor.
Sep 8, 2026 at 5:10 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Sep 13, 2026 at 4:50 AM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Source

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Vendor: Fortinet
Advisory ID: FG-IR-26-174
Last source check: Sep 13, 2026 at 4:50 AM UTC

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What the vendor says is affected

When this advisory changed

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