CVE-2026-0262: Palo Alto PAN-OS DoS Vulnerability

CVE-2026-0262 Overview

CVE-2026-0262 covers multiple denial of service vulnerabilities in Palo Alto Networks PAN-OS® software. An unauthenticated attacker with network access can trigger a denial of service (DoS) condition by sending specially crafted network traffic to an affected device. The flaws are categorized under [CWE-754] (Improper Check for Unusual or Exceptional Conditions). Panorama and Cloud NGFW deployments are not impacted. Palo Alto Networks published the advisory tracking these issues on May 13, 2026.

Critical Impact
Unauthenticated network-based attackers can disrupt availability of PAN-OS firewall services, potentially interrupting traffic inspection and enforcement at the network perimeter.

Affected Products

Palo Alto Networks PAN-OS® software (specific versions per vendor advisory)
Hardware and virtual PAN-OS firewall appliances
Panorama and Cloud NGFW are NOT affected

Discovery Timeline

2026-05-13 - CVE-2026-0262 published to NVD
2026-05-13 - Last updated in NVD database

Technical Details for CVE-2026-0262

Vulnerability Analysis

The advisory describes multiple denial of service conditions within PAN-OS reachable through the network data path. Successful exploitation degrades or halts firewall services, removing inline inspection and policy enforcement until the device recovers. The vulnerability requires no authentication, no privileges, and no user interaction, leaving any PAN-OS instance whose management or data interfaces are reachable by an attacker exposed. Because PAN-OS frequently sits at the network perimeter, service disruption can affect availability of downstream applications and security controls.

Root Cause

The issues map to [CWE-754], improper check for unusual or exceptional conditions. PAN-OS components fail to validate or handle anomalous protocol states encountered while parsing crafted network traffic. The unchecked condition causes the affected process or data plane to enter an error state that results in service disruption rather than graceful recovery.

Attack Vector

Exploitation occurs over the network. An attacker sends specially crafted packets to a vulnerable PAN-OS interface that processes the affected traffic type. No credentials or prior foothold are required. Repeated delivery of the malicious traffic can sustain the denial of service for the duration of the attack. Refer to the Palo Alto Networks Advisory for protocol-level specifics and impacted versions.

Detection Methods for CVE-2026-0262

Indicators of Compromise

Unexpected PAN-OS process restarts, dataplane reboots, or HA failover events correlated with inbound traffic spikes
System log entries reporting crashes, watchdog timeouts, or session table anomalies on PAN-OS devices
Bursts of malformed or atypical protocol traffic targeting firewall interfaces from external sources

Detection Strategies

Monitor PAN-OS system and dataplane logs for repeated daemon restarts or core file generation events
Alert on SNMP availability checks failing against firewall management or data interfaces
Correlate upstream router and switch logs for sudden loss of routing adjacency to PAN-OS devices

Monitoring Recommendations

Forward PAN-OS syslog to a centralized SIEM and create alerts for crash, reboot, and HA failover events
Baseline normal protocol distribution at the perimeter to surface anomalous crafted traffic patterns
Track CPU, memory, and session utilization metrics on PAN-OS appliances for early signs of resource exhaustion

How to Mitigate CVE-2026-0262

Immediate Actions Required

Review the Palo Alto Networks Advisory to identify affected PAN-OS versions in your environment
Apply vendor-supplied fixed PAN-OS releases as soon as they are validated for deployment
Restrict exposure of PAN-OS management and unused data plane services to trusted networks only

Patch Information

Palo Alto Networks has published fixed PAN-OS versions in the security advisory for CVE-2026-0262. Administrators should consult the Palo Alto Networks Advisory for the complete list of affected and remediated versions and upgrade their firewalls accordingly. Panorama and Cloud NGFW require no action for this CVE.

Workarounds

Apply threat prevention signatures and zone protection profiles that drop the crafted traffic patterns described in the vendor advisory
Limit network reachability to PAN-OS interfaces using upstream access control lists where operationally feasible
Enable high availability pairs so that failover preserves service continuity during transient DoS conditions

bash

# Configuration example: restrict management access on PAN-OS
set deviceconfig system permitted-ip <trusted-admin-subnet>
commit