A PAN-OS URL filtering policy misconfiguration could allow a network-based attacker to conduct reflected and amplified TCP denial-of-service (RDoS) attacks. The DoS attack would appear to originate from a Palo Alto Networks PA-Series (hardware), VM-Series (virtual) and CN-Series (container) firewall against an attacker-specified target. To be misused by an external attacker, the firewall configuration must have a URL filtering profile with one or more blocked categories assigned to a source zone that has an external facing interface. This configuration is not typical for URL filtering and, if set, is likely unintended by the administrator. If exploited, this issue would not impact the confidentiality, integrity, or availability of our products. However, the resulting denial-of-service (DoS) attack may help obfuscate the identity of the attacker and implicate the firewall as the source of the attack. We have taken prompt action to address this issue in our PAN-OS software. All software updates for this issue are expected to be released no later than the week of August 15, 2022. This issue does not impact Panorama M-Series or Panorama virtual appliances. This issue has been resolved for all Cloud NGFW and Prisma Access customers and no additional action is required from them.
Conclusion & alert: CVE-2022-0028 is rated Critical Active Threat (90.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 4.68%). Core evidence: CISA KEV confirms active exploitation (added 2022-08-22) affecting Palo Alto Networks / PAN-OS. a weakness (CWE-406) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
: Palo Alto Networks PAN-OS Reflected Amplification Denial-of-Service Vulnerability · CISA KEV detail
: 2022-08-22
: 2022-09-12
: Apply updates per vendor instructions.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-27 | 4.81% | 4.68% | -0.12% |
| 2 | 2026-05-22 | 4.68% | 4.81% | +0.12% |
| 3 | 2025-12-28 | — | 4.68% | — |
Full EPSS history (33 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.6 | 3.1 | HIGH |
|
3.9 | 4.0 | [email protected] |
| 8.6 | 3.1 | HIGH |
|
3.9 | 4.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| paloaltonetworks | pan-os | >= 8.1.0, < 8.1.23 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | >= 9.0.0, < 9.0.16 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | >= 9.1.0, < 9.1.14 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | >= 10.0.0, < 10.0.11 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | >= 10.1.0, < 10.1.6 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | >= 10.2.0, < 10.2.2 | cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 8.1.23 | cpe:2.3:o:paloaltonetworks:pan-os:8.1.23:-:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 9.0.16 | cpe:2.3:o:paloaltonetworks:pan-os:9.0.16:-:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 9.0.16 | cpe:2.3:o:paloaltonetworks:pan-os:9.0.16:h2:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 9.1.14 | cpe:2.3:o:paloaltonetworks:pan-os:9.1.14:-:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 9.1.14 | cpe:2.3:o:paloaltonetworks:pan-os:9.1.14:h1:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 10.0.11 | cpe:2.3:o:paloaltonetworks:pan-os:10.0.11:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 10.1.6 | cpe:2.3:o:paloaltonetworks:pan-os:10.1.6:*:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 10.1.6 | cpe:2.3:o:paloaltonetworks:pan-os:10.1.6:h3:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 10.2.2 | cpe:2.3:o:paloaltonetworks:pan-os:10.2.2:-:*:*:*:*:*:* |
| paloaltonetworks | pan-os | 10.2.2 | cpe:2.3:o:paloaltonetworks:pan-os:10.2.2:h1:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://security.paloaltonetworks.com/CVE-2022-0028 | Mitigation Third Party Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-0028 | US Government Resource |