Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability

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

Published 31 Aug 2026Updated 31 Aug 202614 sources
CVSS 0.0 PoC CANDIDATE△ CISA KEV

What happened

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

Affected versions

FortiOS and FortiProxy SSL-VPN: See original advisory Fixed: See vendor advisory.

Why it matters

This source correlation may provide earlier visibility while structured CVE metadata is still being updated.

Detection & mitigation

  • Review the original advisory and validate affected versions.
  • Apply vendor-provided updates or mitigations when available.

Public PoC references

RepositoryAuthorFirst seenReference
PoC-in-GitHub · rio128128/CVE-2023-27997-POCPOC FortiOS SSL-VPN buffer overflow vulnerability★ 27rio1281282023-06-16CandidatePoC-in-GitHub · BishopFox/CVE-2023-27997-checkSafely detect whether a FortiGate SSL VPN instance is vulnerable to CVE-2023-27997 based on response timing★ 135BishopFox2023-06-16CandidatePoC-in-GitHub · imbas007/CVE-2023-27997-Check★ 1imbas0072023-06-22CandidatePoC-in-GitHub · puckiestyle/cve-2023-27997★ 0puckiestyle2023-06-23CandidatePoC-in-GitHub · TechinsightsPro/ShodanFortiOSSearch vulnerable FortiOS devices via Shodan (CVE-2023-27997)★ 2TechinsightsPro2023-07-11CandidatePoC-in-GitHub · Cyb3rEnthusiast/CVE-2023-27997How to get access via CVE-2022-27997★ 0Cyb3rEnthusiast2023-09-03CandidatePoC-in-GitHub · lexfo/xortigate-cve-2023-27997xortigate-cve-2023-27997★ 62lexfo2023-10-12CandidatePoC-in-GitHub · delsploit/CVE-2023-27997★ 9delsploit2023-10-12CandidatePoC-in-GitHub · node011/CVE-2023-27997-POCFortigate SSL VPN buffer overflow exploit★ 0node0112024-11-14CandidatePoC-in-GitHub · onurkerembozkurt/fgt-cve-2023-27997-exploitFortiGate SSL-VPN CVE-2023-27997 Exploit PoC Script with ROP Chain★ 0onurkerembozkurt2025-04-18CandidatePoC-in-GitHub · Vampsecure-Labs/vamp-forticheckVampSecure Labs: FortiOS CVE scanner (CVE-2018-13379, CVE-2022-40684, CVE-2023-27997, CVE-2024-21762)★ 0Vampsecure-Labs2026-07-31CandidatePoC-in-GitHub · abraxas/Fortigate-SSL-VPN-Exploit-KitThe FortiGate SSL-VPN pot of gold. CVE-2024-21762 and CVE-2023-27997. 79 working exploit clients. 53 hardware SKUs. 55 FortiOS builds.★ 0abraxas2026-09-01Candidate