ID :ISA-2026-057
Critical alertActiveCVSS 9.1/10IservicesCSIRT

Authentication bypass affecting Palo Alto Networks PAN-OS

Executive Summary

A vulnerability affecting Palo Alto Networks PAN-OS would allow an unauthenticated attacker to bypass authentication mechanisms and establish unauthorized VPN connections on affected systems.

Published on June 19, 2026 at 01:00 AM by Iservices Csirt9 views

Description

Technical context and vulnerability details

PAN-OS is the operating system for Palo Alto Networks' next-generation firewalls, used to secure corporate networks, in particular via the GlobalProtect component for VPN access. This system is affected by a vulnerability labeled CVE-2026-0257 resulting from the lack of validation and integrity control of authentication cookies. Exploitation of this vulnerability would allow an unauthenticated attacker to forge a valid cookie to bypass security controls and establish an unauthorized VPN session to the internal network. It is classified critical with a severity score of 9.1 according to CVSS V3.1.

Potential Risks & Impact

Potential consequences upon exploitation

  • Bypassing authentication mechanisms;
  • Establishing unauthorized VPN connections;
  • Data privacy breach;
  • Compromise of system and internal network integrity;

Affected systems

Products, components and targeted versions

  • PAN-OS 10.2 versions prior to 10.2.7-h34, 10.2.10-h36, 10.2.13-h21, 10.2.16-h7, and 10.2.18-h6;
  • PAN-OS 11.1 versions prior to 11.1.4-h33, 11.1.6-h32, 11.1.7-h6, 11.1.10-h25, 11.1.13-h5 and 11.1.15;
  • PAN-OS 11.2 versions prior to 11.2.4-h17, 11.2.7-h14, 11.2.10-h7 and 11.2.12;
  • PAN-OS 12.1 versions prior to 12.1.4-h6 and 12.1.7;
  • Prisma Access 11.2.0 versions prior to 11.2.7-h13;
  • Prisma Access 10.2.0 versions prior to 10.2.10-h36;

Recommended Remediations & Actions

Immediate actions and recommended mitigations

  • Update PAN-OS to its latest stable version;
  • Temporarily disable the “Authentication Override” feature if the update cannot be applied immediately;

Advisory Specifications

ISA-2026-057
CVSS scoreCRITICAL
9.1/ 10.0
0.0 (Low)5.0 (Med)10.0 (Crit)
PriorityCritical
StatusActive
Typesecurite
Published onJune 19, 2026 at 01:00 AM
OrigineIservicesCSIRT
Audience9 views

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