Fortinet Releases FortiMail Updates to Patch Zero-Day CVE-2026-104286
Fortinet has started distributing updates for its FortiMail email security product to remediate the zero-day vulnerability tracked as CVE-2026-104286.
The flaw permits an attacker to write arbitrary files to the system by sending a specially crafted HTTP request without requiring authentication. Fortinet confirmed that the vulnerability was already being exploited in the wild at the time the advisory was first published.
On October 1, 2026, the vendor released security advisory FG-IR-26-175 and began sharing Indicators of Compromise (IoC) data while preparing patches. The advisory also included recommended workarounds for organizations that could not immediately apply updates.
Five days later, on October 5, 2026, Fortinet updated the advisory and made the fixed releases available: FortiMail 8.0.2, 7.6.7, and 7.4.9. Customers are urged to install the updates as soon as possible.
The 7.2 branch remains affected. Fortinet recommends that organizations still using this branch migrate to the 7.4 branch or newer to obtain the necessary protection.
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