CRITICALZero Day
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Critical FortiMail Zero-Day Flaw Exploited in Attacks Allows Unauthenticated Arbitrary File Writes

·Source: The Hacker News

Updated:

Executive Summary

The U.S. Cybersecurity and Infrastructure Security Agency (CISA), on Thursday, added a critical security flaw impacting Fortinet FortiMail to its Known Exploited Vulnerabilities (KEV) catalog, following reports of active exploitation. The vulnerability, tracked as CVE-2026-104286 (CVSS score: 9.8), allows unauthenticated attackers to write arbitrary files on the underlying system. "An improper

Analysis

The U.S. Cybersecurity and Infrastructure Security Agency (CISA), on Thursday, added a critical security flaw impacting Fortinet FortiMail to its Known Exploited Vulnerabilities (KEV) catalog, following reports of active exploitation. The vulnerability, tracked as CVE-2026-104286 (CVSS score: 9.8), allows unauthenticated attackers to write arbitrary files on the underlying system. "An improper

Indicators of Compromise (1)

CVE (1)
CVE-2026-104286
NVDMITRE CVE
Source Attribution

Originally published by The Hacker News on Oct 2, 2026.

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