Exploited CVEs / Fortinet / CVE-2020-12812
CVE-2020-12812
Fortinet FortiOS SSL VPN Improper Authentication Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted, and the vulnerability is known to be used in ransomware campaigns. Federal agencies were required to remediate by 2022-05-03 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Fortinet PSIRT Advisories, linked below.
Actively exploited Fortinet FortiOS vulnerability, Critical severity, CVSS 9.8. Added to the CISA KEV catalog 2021-11-03.
Risk summary
Updated July 26, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2020-12812
A username case change should never defeat two-factor authentication, but on vulnerable Fortinet FortiOS SSL VPN builds it does: altering the case of the username lets a user log in without being prompted for the FortiToken second factor. Ransomware operators have used this, which fits their pattern of favoring VPN credentials as an entry point. It undermines the exact control most organizations count on to protect remote access.
Do this: Upgrade FortiOS on SSL VPN gateways and review VPN sign-in logs for logins that skipped second-factor prompts.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2020-12812
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2020-12812
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
CISA required action
Federal (BOD 22-01) remediation due date: 2022-05-03 (past due).
Apply updates per vendor instructions.
Official fix for CVE-2020-12812
The authoritative fix and affected-version list are published by the vendor. Find the FortiOS advisory on Fortinet PSIRT Advisories.
Common questions about CVE-2020-12812
Is CVE-2020-12812 actively exploited?
Yes. CVE-2020-12812 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 49%. CISA also reports it is known to be used in ransomware campaigns.
What is the CISA deadline and required action for CVE-2020-12812?
CISA set the federal (BOD 22-01) remediation due date at 2022-05-03, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.
What fixes CVE-2020-12812?
The authoritative fix is in the vendor advisory: see Fortinet PSIRT Advisories for the patched FortiOS versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.
Can I ask my own AI about CVE-2020-12812?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2020-12812's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).
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Authoritative references
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.
