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TI-2021-17891 Aliases CVE-2021-41027GHSA-jgm2-2f8q-fj63

Out-of-bounds write in Fortinet FortiWeb

Priority LOW 35CWE-787Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

A stack-based buffer overflow in Fortinet FortiWeb version 6.4.1 and 6.4.0, allows an authenticated attacker to execute unauthorized code or commands via crafted certificates loaded into the device.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00163 5th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FortinetFortinet FortiWebFortiWeb 6.4.1, 6.4.0—No fix listedCNA
  • Fortinet FortiWeb VendorFortinet Affected FortiWeb 6.4.1, 6.4.0 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:fortinet:fortiweb:6.4.0:*:*:*:*:*:*:*6.4.0VulnerableFortinet
cpe:2.3:a:fortinet:fortiweb:6.4.1:*:*:*:*:*:*:*6.4.1VulnerableFortinet
  • cpe:2.3:a:fortinet:fortiweb:6.4.0:*:*:*:*:*:*:* Versions 6.4.0 Vulnerable ·Fortinet
  • cpe:2.3:a:fortinet:fortiweb:6.4.1:*:*:*:*:*:*:* Versions 6.4.1 Vulnerable ·Fortinet

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-41027
  2. 2026-10-03 Alias added: GHSA-jgm2-2f8q-fj63

References

Patch 1

  • TI-2026-20057 Authentication bypass in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.4
  • TI-2025-39856 Path traversal in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.4
  • TI-2025-18919 SQL injection in Fortinet FortiWeb KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-35886 OS command injection in Fortinet FortiWeb KEVCVSS 3.1MEDIUM 6.7
  • TI-2021-05113 OS command injection in Fortinet FortiWeb CVSS 3.1HIGH 8.8
  • TI-2021-18960 Stack-based buffer overflow in Fortinet FortiWeb CVSS 3.1CRITICAL 9.8
See all 125 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences