Is CVE-2021-26109 being actively exploited?

CVE-2021-26109 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2021-26109?

CVE-2021-26109 has a CVSS 3.1 base score of 8.1 (HIGH).

CVE-2021-26109

HIGH · CVSS 8.1EPSS 1.9%EU EUVD

An integer overflow or wraparound vulnerability in the memory allocator of SSLVPN in FortiOS before 7.0.1 may allow an unauthenticated attacker to corrupt control data on the heap via specifically crafted requests to SSLVPN, resulting in potentially arbitrary code execution.

Key facts

CVSS score: 8.1 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-190
EPSS score: 1.9% (79th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-12930)
Published: December 8, 2021
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-12930 in the EU Vulnerability Database. Last updated in EUVD on October 25, 2024.

View on the EU Vulnerability Database

Affected products

fortinet / fortios
fortinet / fortios

Certified products that may be affected

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

FortiGate/FortiOS Version 6.2.7 - Fortinet, Inc. - Common Criteria 559-LSS - archived

References

https://fortiguard.com/advisory/FG-IR-21-049(Patch, Vendor Advisory)

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

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