Exploited vulnerability · CISA KEV

Is CVE-2022-42475 exploited? Yes: in CISA KEV since 13 Dec 2022

Gociux · Fortinet FortiOS · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2022-42475, Fortinet FortiOS Heap-Based Buffer Overflow Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 13 Dec 2022. It is known to be used in ransomware campaigns. It affects Fortinet FortiOS, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

Multiple versions of Fortinet FortiOS SSL-VPN contain a heap-based buffer overflow vulnerability which can allow an unauthenticated, remote attacker to execute arbitrary code or commands via specifically crafted requests.

What to do

1. Check whether you run it. Look for FortiOS in your asset inventory, including appliances and cloud images. Stack check lists every exploited Fortinet CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 2 Jan 2023.
4. Get told next time. Email alerts when CISA adds a CVE for Fortinet.

Other exploited CVEs in FortiOS

• CVE-2025-68686: Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (27 Jul 2026)
• CVE-2019-6693: Fortinet FortiOS Use of Hard-Coded Credentials Vulnerability (25 Jun 2025)
• CVE-2024-21762: Fortinet FortiOS Out-of-Bound Write Vulnerability (9 Feb 2024)
• CVE-2022-41328: Fortinet FortiOS Path Traversal Vulnerability (14 Mar 2023)
• CVE-2021-44168: Fortinet FortiOS Arbitrary File Download (10 Dec 2021)
• CVE-2019-5591: Fortinet FortiOS Default Configuration Vulnerability (3 Nov 2021)

References

• www.fortiguard.com/psirt/FG-IR-22-398
• nvd.nist.gov/vuln/detail/CVE-2022-42475

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in December 2022 · Fortinet scorecard · act-now radar.