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CVE-2026-0257: Palo Alto Networks PAN-OS Authentication Bypass Vulnerability

CVE-2026-0257 is rated critical with a CVSS v3.1 base score of 9.1 and affects Palo Alto Networks PAN-OS, along with 2 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-05-29, which means exploitation in the wild has been observed.

Vulnerability description

Authentication bypass vulnerabilities in the GlobalProtect portal and gateway of Palo Alto Networks PAN-OS® software allows the attacker to bypass security restrictions and establish an unauthorized VPN connection. Panorama and Cloud NGFW are not impacted by these issues.

Severity breakdown

CVSS v3.1 9.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: None. No effect on availability.

Underlying weakness

CWE-565: Reliance on Cookies without Validation and Integrity Checking

The product relies on the existence or values of cookies when performing security-critical operations, but it does not properly ensure that the setting is valid for the associated user.

Affected products

  • Paloaltonetworks Pan OS: before 10.2.7; 10.2.7; 10.2.7 h1; 10.2.7 h12; 10.2.7 h16; 10.2.7 h18; 10.2.7 h19; 10.2.7 h21; 10.2.7 h24; 10.2.7 h3; 10.2.7 h32; 10.2.7 h6
  • Paloaltonetworks Prisma Access: all versions listed by NVD
  • Siemens Ruggedcom Ape1808 Firmware: all versions listed by NVD

References