Is CVE-2023-27997 being actively exploited?

Yes. CVE-2023-27997 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on June 13, 2023.

What is the CVSS score for CVE-2023-27997?

CVE-2023-27997 has a CVSS 3.1 base score of 9.8 (CRITICAL).

CVE-2023-27997

CRITICAL · CVSS 9.8CISA KEV: actively exploitedEPSS 85.7%EU EUVD: exploited

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.

Key facts

CVSS score: 9.8 (v3.1)
Severity: CRITICAL
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-122
EPSS score: 85.7% (100th percentile)
In CISA KEV: Yes, added June 13, 2023
In EU EUVD: Yes (EUVD-2023-31722)
Published: June 13, 2023
NVD last modified: July 31, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

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

Added to the KEV catalog on June 13, 2023; federal remediation due July 4, 2023. Known to be used in ransomware campaigns.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2023-31722 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on July 31, 2026.

View on the EU Vulnerability Database

Affected products

fortinet / fortigate 6000
fortinet / fortigate 7000
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortios
fortinet / fortiproxy

Certified products that may be affected

2 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Fortinet, Inc. FortiOS 7.0.7 - Fortinet, Inc. - Common Criteria NSCIB-CC-0590233-CR - active
FortiGate/FortiOS Version 6.2.7 - Fortinet, Inc. - Common Criteria 559-LSS - archived

References

https://fortiguard.com/psirt/FG-IR-23-097(Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27997(US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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