CVE-2021-42756 exploit

Exploit for CVE-2021-42756. CVSS 9.8.

Published 5 Sep 2026Updated 5 Sep 20269 sources
CVSS 9.8 PoC CANDIDATE

What happened

Stack overflow in FortiWeb proxy daemon MitB protection enables unauthenticated code execution.

Affected versions

Unknown product: 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