ZeroHour

CVE-2026-0310

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Buffer Overflow in PAN-OS XML Processing Enables Root RCE on PA-Series Firewalls

CVSS 4.0
7.2 high
EPSS
Published
()
Modified
AI analysis

Palo Alto Networks PAN-OS contains a buffer overflow (CWE-787, out-of-bounds write) in its XML processing functionality. An unauthenticated attacker with network access to the management web interface or the dataplane interface can send malicious XML input to trigger the flaw. On PA-Series hardware firewalls this allows arbitrary code execution with root privileges, while on VM-Series virtual firewalls the impact is limited to a denial-of-service condition. Panorama centralized management is also affected, and exposure is greatly reduced when the management interface is restricted to trusted internal IP addresses per vendor best practice. As of this analysis there is no known public proof-of-concept, no CISA KEV listing, and no confirmed exploitation in the wild (CVSS 4.0 marks exploitability as unproven).

What to do: Patch to a fixed PAN-OS release as soon as Palo Alto Networks publishes fixed versions, prioritizing PA-Series firewalls and Panorama where root code execution is possible; the advisory does not name specific fixed builds, so consult the vendor advisory for branch-specific updates. Until patching, restrict access to the management web and dataplane interfaces to trusted internal IP addresses per the vendor's management-access hardening guidance, and audit which firewalls, VM-Series instances, and Panorama servers have these interfaces reachable from untrusted networks. Monitor Palo Alto Networks advisories for updates on exploitation status and proof-of-concept releases.

Affected
Palo Alto Networks PAN-OS on PA-Series firewalls
Palo Alto Networks PAN-OS on VM-Series firewalls
Palo Alto Networks Panorama
Estimated exposure
largetens of thousands of exposed PAN-OS systems (public internet scans have historically shown on the order of 10,000-50,000 PAN-OS management and dataplane… — Public internet-wide scans and prior PAN-OS vulnerability surveys have repeatedly found tens of thousands of PAN-OS management/dataplane interfaces exposed online, while Palo Alto Networks' overall firewall installed base spans hundreds of…

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

A buffer overflow vulnerability in the XML processing functionality of Palo Alto Networks PAN-OS® software enables an unauthenticated attacker with network access to the management web or dataplane interface to cause a denial of service (DoS) condition on VM-Series firewalls or execute arbitrary code with root privileges on the PA-Series firewalls. The security risk posed by this issue is minimized when the management interface is restricted to only trusted internal IP addresses according to our recommended best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 . Panorama is impacted by this vulnerability.

Weakness
CWE-787
Vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:U/V:D/RE:M/U:Red

In the news

Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories

Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.

Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.

Palo Alto PAN-OS Buffer Overflow Lets Attackers Execute Arbitrary Code as Root

Palo Alto Networks fixed CVE-2026-0310, a CVSS 9.2 unauthenticated PAN-OS buffer overflow enabling root code execution on PA-Series firewalls.

Palo Alto Networks published an advisory on September 9, 2026 for CVE-2026-0310, a CWE-787 out-of-bounds write in PAN-OS XML processing with a CVSS v4.0 base score of 9.2, affecting the management and dataplane interfaces. Unauthenticated attackers could execute arbitrary code as root on PA-Series hardware firewalls, while VM-Series faces denial-of-service impact and Prisma Access and Cloud NGFW have reduced, authenticated exposure. Affected releases include PAN-OS 10.2, 11.1, 11.2, 12.1, and 12.2 before fixed maintenance releases such as 12.2.3, 12.1.4-h10, 11.2.13-h2, 11.1.16-h2, and 10.2.18-h10; no workaround is available. Palo Alto is not aware of malicious exploitation but classifies remediation urgency as highest.

GBHackers · 5d agoVulnerabilityCVE-2026-0310

Palo Alto PAN-OS Vulnerability Enables Arbitrary Code Execution as Root User

Palo Alto Networks patched CVE-2026-0310, an unauthenticated XML-processing buffer overflow in PAN-OS allowing root code execution on PA-Series firewalls.

Palo Alto Networks disclosed CVE-2026-0310, an out-of-bounds write (CWE-787) in PAN-OS XML processing with a CVSS-B base score of 9.2 and CVSS-BT of 7.2. An unauthenticated attacker with network access to a vulnerable management or dataplane interface can send crafted XML to execute arbitrary code as root on PA-Series appliances. On VM-Series the impact is limited to denial-of-service, while Prisma Access and Cloud NGFW require authentication and carry lower risk. Fixed releases include 12.2.3, 12.1.10, 11.2.13-h2, 11.1.16-h2, and 10.2.18-h10; no workaround exists beyond restricting management interface access.

Palo Alto Networks security advisory (AV26-905)

Canada's Cyber Centre relayed Palo Alto Networks advisories covering PAN-OS, Cloud NGFW, Prisma Access, and Prisma Browser vulnerabilities, including PAN-OS CVE-2026-0310 buffer overflow.

The Canadian Centre for Cyber Security issued advisory AV26-905, noting that as of September 10, 2026, multiple Palo Alto Networks products are affected by vulnerabilities. Affected products include Cloud NGFW on AWS and Azure, multiple PAN-OS versions, Prisma Access, and Prisma Browser prior to 151.26.5.170. The advisory references CVE-2026-0310, a PAN-OS buffer overflow via XML processing (PAN-SA-2026-0012), and the September 2026 Chromium monthly vulnerability update. Administrators are encouraged to review the vendor links and apply available updates.