CVE-2026-0257
Palo Alto Networks PAN-OS Authentication Bypass Vulnerability
Palo Alto Networks PAN-OS
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.
Ransomware groups exploiting CVE-2026-0257
Qilin ransomware was first observed in July of 2022. Qilin Ransomware is written in Golang and supports multiple encryption modes; all of which are controlled by the operator. Qilin actors practice double extortion – demanding payment for a decryptor, as well
Exploitation is attributed to these groups across their recorded activity. It does not follow that every organisation they listed was reached through CVE-2026-0257 — the source data does not record an entry point per incident.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 29 May 2026. US federal agencies were required to remediate it by 1 June 2026. CISA records this vulnerability as known to be used in ransomware campaigns.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 96.4%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Recent listings by these groups
Disclosures from the groups above, newest first.
Frequently asked questions
Is CVE-2026-0257 being exploited by ransomware groups?
Yes. CVE-2026-0257 is recorded as exploited by Qilin. Between them these groups account for 2,298 victim disclosures in this database. CISA also records this vulnerability as used in ransomware campaigns.
What does CVE-2026-0257 affect?
CVE-2026-0257 affects Palo Alto Networks PAN-OS. 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.
How severe is CVE-2026-0257?
CVE-2026-0257 is rated CRITICAL with a CVSS base score of 9.1. EPSS puts the probability of exploitation in the next 30 days at 96.4%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 1 June 2026.
How should organisations respond to CVE-2026-0257?
Apply the vendor patch for Palo Alto Networks PAN-OS as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.