Exploited CVEs / Palo Alto Networks / CVE-2020-2021
CVE-2020-2021
Palo Alto Networks PAN-OS Authentication Bypass 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 2022-04-15 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Palo Alto Networks Security Advisories, linked below.
Actively exploited Palo Alto Networks PAN-OS vulnerability, Critical severity, CVSS 10.0. Added to the CISA KEV catalog 2022-03-25.
Risk summary
Updated July 28, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2020-2021
When SAML authentication is in use, this Palo Alto Networks PAN-OS flaw lets attackers bypass authentication entirely, a perfect 10.0 CVSS with confirmed ransomware use. An identity check failing open on a firewall or VPN gateway is an identity-layer catastrophe rather than a routine software bug. Its low 4 percent EPSS reflects the specific SAML precondition, not low impact.
Do this: Verify PAN-OS devices using SAML are patched for CVE-2020-2021 and review authentication logs from any period spent unpatched.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2020-2021
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2020-2021
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: 2022-04-15 (past due).
Apply updates per vendor instructions.
Official fix for CVE-2020-2021
The authoritative fix and affected-version list are published by the vendor. Find the PAN-OS advisory on Palo Alto Networks Security Advisories.
Common questions about CVE-2020-2021
Is CVE-2020-2021 actively exploited?
Yes. CVE-2020-2021 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2022-03-25, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 4.4%. CISA also reports it is known to be used in ransomware campaigns.
What is the CISA deadline and required action for CVE-2020-2021?
CISA set the federal (BOD 22-01) remediation due date at 2022-04-15, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.
What fixes CVE-2020-2021?
The authoritative fix is in the vendor advisory: see Palo Alto Networks Security Advisories for the patched PAN-OS 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-2020-2021?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2020-2021'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).
More exploited Palo Alto Networks CVEs
The newest Palo Alto Networks entries on the CISA KEV catalog:
All Palo Alto Networks exploited CVEs on one page: Palo Alto Networks vulnerabilities actively exploited.
Authoritative references
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.
