# CVE-2026-0310: PAN-OS XML Processing Out-of-Bounds Write Enables Unauthenticated Root RCE

> A CWE-787 out-of-bounds write in PAN-OS XML processing lets an unauthenticated network attacker with access to the management web interface or dataplane interface execute arbitrary code as root on PA-Series firewalls, or cause a denial-of-service condition on VM-Series. Palo Alto Networks discovered the flaw internally; as of publication (2026-09-09/10) there is no known in-the-wild exploitation, no public proof-of-concept, and it is not in the CISA KEV catalog.

- **Published:** 2026-09-10T00:00:00Z
- **Last reviewed:** 2026-09-10T00:00:00Z
- **Canonical:** https://intel.threadlinqs.com/threat/TL-2026-2440
- **ID:** TL-2026-2440
- **Severity:** CRITICAL (CVSS 9.2)
- **Category:** VULNERABILITY
- **Status:** ACTIVE
- **Detections:** 9 · **IOCs:** 8 (full data via the Threadlinqs MCP server — Purple tier)
- **CVEs:** CVE-2026-0310

## Description

CVE-2026-0310 is a buffer overflow (CWE-787, out-of-bounds write; CAPEC-100 Overflow Buffers) in the XML processing functionality of Palo Alto Networks PAN-OS. An unauthenticated attacker who can reach the management web interface or the dataplane interface can send specially crafted XML data to trigger memory corruption. On PA-Series hardware firewalls the flaw can be leveraged for arbitrary code execution with root privileges; on VM-Series virtual firewalls the same flaw is limited to a denial-of-service condition. Panorama is impacted across the same vulnerable PAN-OS branches. Cloud NGFW on AWS and Azure (all versions as of disclosure) are also affected, and Prisma Access is affected at materially lower risk (CVSS v4.0 4.8, adjacent-network vector, authentication required), substantially reducing its exposure relative to on-premises PA-Series/VM-Series/Panorama deployments.

No special configuration is required for a device to be vulnerable, and the vendor states no workaround exists short of upgrading; risk is minimized (not eliminated) by restricting the management interface to trusted internal IP addresses. Exploit complexity is rated high (CVSS v4.0 AC:H) but the base severity for the PA-Series root-RCE scenario is 9.2 (CRITICAL) -- network attack vector, no privileges or user interaction required, full confidentiality/integrity/availability impact -- while the threat-adjusted CVSS-BT score (reflecting unreported exploit maturity) is 7.2. VM-Series scores CVSS-B 8.7 / CVSS-BT 6.6 (availability impact only). The vendor's own risk narrative for a successfully exploited PA-Series device describes an attacker able to alter security policies, inspect or redirect inspected traffic, deploy persistence, and steal device configuration -- full compromise of a network perimeter/boundary control point, not merely a crash. Independent reporting adds that root access could let an attacker disable protections, intercept or manipulate traffic, and use the device as an internal pivot point for further network attacks.

Palo Alto Networks discovered and disclosed the vulnerability internally; there is no confirmed threat-actor exploitation, no public PoC, and it does not appear in the CISA Known Exploited Vulnerabilities catalog as of 2026-09-10 (confirmed against CISA's recent KEV-addition alerts, none of which name CVE-2026-0310). Given the criticality of PAN-OS firewalls as internet- and network-facing perimeter devices, and the industry-wide history of PAN-OS management-interface vulnerabilities being weaponized shortly after disclosure, defenders should treat this as a high-priority, patch-now advisory even in the absence of confirmed exploitation.

## MITRE ATT&CK

- T1595.002 Vulnerability Scanning
- T1190 Exploit Public-Facing Application
- T1136.001 Local Account
- T1098 Account Manipulation
- T1686 Disable or Modify System Firewall
- T1685 Disable or Modify Tools
- T1557 Adversary-in-the-Middle
- T1602.002 Network Device Configuration Dump
- T1499.004 Application or System Exploitation

## Sources

- [CVE-2026-0310 PAN-OS: Buffer Overflow Vulnerability via XML Processing](https://security.paloaltonetworks.com/CVE-2026-0310)
- [CVE-2026-0310: Critical PAN-OS Buffer Overflow Flaw](https://socprime.com/blog/cve-2026-0310-analysis/)
- [Palo Alto PAN-OS Vulnerability Enables Arbitrary Code Execution as Root User](https://cybersecuritynews.com/palo-alto-pan-os-vulnerability-code-execution/)
- [Palo Alto PAN-OS Buffer Overflow Lets Attackers Execute Arbitrary Code as Root](https://gbhackers.com/palo-alto-pan-os-buffer-overflow/)
- [CVE-2026-0310: PAN-OS Buffer Overflow Flaw Allows Execute Arbitrary Code with Root Privileges](https://securityonline.info/pan-os-buffer-overflow-flaw/)
- [Palo Alto PAN-OS Flaw Lets Unauthenticated Attackers Execute Code as Root](https://cyberpress.org/palo-alto-pan-os-flaw/)
- [CVE-2026-0310 Detail](https://nvd.nist.gov/vuln/detail/CVE-2026-0310)
- [NVD CVE-2026-0310 API Record](https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-0310)

## Full data

Detection queries (Splunk SPL / Microsoft KQL / Sigma) and IOC values require the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp

Canonical: https://intel.threadlinqs.com/threat/TL-2026-2440