Patch days / May 2026

Fortinet PSIRT Monthly Advisories — May 2026

Tuesday, 12 May 2026

Vulnerabilities: 11
Critical: 2
High: 1
Zero-days: 0
Public exploit: 1

Exploited 0

Confirmed exploited (CISA KEV, ENISA). "Zero-day" means exploitation was known by the patch day — install these first.

None of this release's vulnerabilities is known to be exploited so far.

Critical 2

Critical 9.1
CVE-2026-44277 Public exploit A improper access control vulnerability in Fortinet FortiAuthenticator 8.0.2, FortiAuthenticator 8.0.0, FortiAuthenticator 6.6.0 through 6.6.8, FortiAuthentica…
Critical 9.1
CVE-2026-26083 A missing authorization vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.1, FortiSandbox 4.4.0 through 4.4.8, FortiSandbox 4.2 all versions, FortiSandb…

All vulnerabilities 11

Critical2 Show

High1 Show

High 8.3
CVE-2025-53844 A out-of-bounds write vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11 allows attacker to execu…

Medium7 Show

Low1 Show

Low 2.1
CVE-2026-44278 A use of hard-coded cryptographic key vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.2, FortiClientWindows 7.2 all versions may allow attacker …