CVE-2026-0310: Palo Alto PAN-OS Buffer Overflow Vulnerability

CVE-2026-0310 Overview

CVE-2026-0310 is a buffer overflow vulnerability [CWE-787] in the XML processing functionality of Palo Alto Networks PAN-OS® software. An unauthenticated attacker with network access to the management web interface or dataplane interface can trigger the flaw. Exploitation causes a denial of service (DoS) condition on VM-Series firewalls or arbitrary code execution with root privileges on PA-Series firewalls. Panorama management appliances are also impacted. Restricting the management interface to trusted internal IP addresses reduces the exposed attack surface.

Critical Impact
Unauthenticated network attackers can execute code as root on PA-Series firewalls, granting full control of perimeter security infrastructure.

Affected Products

Palo Alto Networks PAN-OS software (PA-Series firewalls)
Palo Alto Networks PAN-OS software (VM-Series firewalls)
Palo Alto Networks Panorama

Discovery Timeline

2026-09-10 - CVE-2026-0310 published to NVD
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-0310

Vulnerability Analysis

The flaw resides in the XML parsing routines used by PAN-OS to handle inbound requests on both the management web interface and the dataplane interface. An attacker sends crafted XML content that exceeds the bounds of a fixed-size buffer during processing. The out-of-bounds write [CWE-787] corrupts adjacent memory structures on the target device.

On PA-Series hardware firewalls, memory corruption is reachable in a context that yields arbitrary code execution with root privileges. On VM-Series virtualized firewalls, the same code path terminates the affected process and produces a denial of service. Panorama, which shares the affected XML handling code, is also vulnerable.

Exploitation requires no authentication and no user interaction. Attackers only need network reachability to the management or dataplane interface.

Root Cause

The root cause is missing or insufficient length validation in an XML processing routine within PAN-OS. Attacker-controlled input written past the boundaries of a fixed buffer overwrites adjacent memory. This condition maps to CWE-787: Out-of-bounds Write.

Attack Vector

The attack vector is network based. An attacker submits a crafted XML payload to a listener on the PAN-OS management web interface or the dataplane interface. No credentials or user interaction are required. Devices exposing management interfaces to untrusted networks face the highest risk. Refer to the Palo Alto Networks security advisory for CVE-2026-0310 for advisory details.

Detection Methods for CVE-2026-0310

Indicators of Compromise

Unexpected process crashes, restarts, or core dumps on PAN-OS devices, particularly for XML-handling components.
Unauthenticated HTTP or HTTPS requests to the management interface from unknown source addresses containing malformed or oversized XML payloads.
New or unexpected root-owned processes, cron entries, or outbound connections originating from PA-Series firewalls.
Configuration changes on Panorama or managed firewalls that do not correlate to a known administrator session.

Detection Strategies

Inspect PAN-OS system and traffic logs for anomalous XML requests targeting the management or dataplane interface.
Alert on repeated authentication-less connections to the management interface from external or non-approved IP ranges.
Correlate firewall device telemetry with network flow data to identify command-and-control traffic originating from firewall appliances.

Monitoring Recommendations

Forward PAN-OS and Panorama logs to a centralized SIEM or data lake for continuous review.
Monitor management interface exposure using external attack surface scans to confirm interfaces remain restricted.
Track firmware and content versions across the fleet to identify unpatched devices.

How to Mitigate CVE-2026-0310

Immediate Actions Required

Apply the fixed PAN-OS releases from Palo Alto Networks as soon as they are available for your platform.
Restrict access to the management web interface to trusted internal IP addresses only, following the vendor's best practice deployment guidelines.
Audit dataplane interface exposure and remove any unnecessary internet-facing listeners.
Review firewall and Panorama logs for signs of exploitation attempts predating the patch.

Patch Information

Palo Alto Networks publishes fixed versions and workarounds in the official security advisory for CVE-2026-0310. Consult the advisory to identify the corresponding fixed release for each deployed PAN-OS train and for Panorama.

Workarounds

Limit management interface access to a dedicated management VLAN or jump host reachable only from trusted administrator networks.
Place PAN-OS management interfaces behind a VPN and disallow direct internet access.
Enforce network access control lists that permit only known administrator source IP addresses to reach management services.

bash

# Example: restrict management interface to trusted subnets in PAN-OS CLI
configure
set deviceconfig system permitted-ip 10.0.0.0/24
set deviceconfig system permitted-ip 192.168.100.5/32
commit