CVE-2026-0257 — Paloaltonetworks Pan-Os

As of 2026-05-29, CVE-2026-0257 is a CRITICAL-severity vulnerability in Paloaltonetworks Pan-Os, CVSS v3.1 9.1, EPSS 0.0% (20.3th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-29), with a US federal remediation deadline of 2026-06-01, and CISA links it to known ransomware campaigns. Threadlinqs Intelligence links 5 tracked threat campaigns to CVE-2026-0257, most recently “2026 Ransomware Surge Targeting US Organizations: Identity-First Compromise, BYOVD, and Living-Off-the-Cloud Exfiltration (Qilin, Akira, Clop, INC Ransom, Play, DragonForce, Sinobi)”.

Last updated: 2026-05-29

What is CVE-2026-0257?

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.

The record classifies CVE-2026-0257 under weakness class CWE-565. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 123 days ago.

Severity and exploitation probability

CVSS v3.1 base score

9.1 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v4.0 base score

7.8
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N/E:A/AU:N/R:A/V:D/RE:M/U:Red

EPSS (FIRST)

0.0% probability of exploitation in the next 30 days, higher than 20.3% of all scored CVEs

CISA KEV

Listed since 2026-05-29, federal remediation deadline 2026-06-01 — used in known ransomware campaigns

Threadlinqs priority

10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum

Published

2026-05-13, last modified 2026-05-29

Is CVE-2026-0257 being exploited?

CISA added CVE-2026-0257 to the Known Exploited Vulnerabilities catalog on 2026-05-29, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-01 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 20 in the Threadlinqs vulnerability feed.

Affected products and versions

• Paloaltonetworks: Pan-Os, Prisma Access

How to fix CVE-2026-0257

Vendor advisory: https://security.paloaltonetworks.com/CVE-2026-0257. Because CVE-2026-0257 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-01. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-0257

5 tracked threats in the Threadlinqs corpus reference CVE-2026-0257, either in the campaign’s CVE list or as an indicator on the campaign record.

• 2026 Ransomware Surge Targeting US Organizations: Identity-First Compromise, BYOVD, and Living-Off-the-Cloud Exfiltration (Qilin, Akira, Clop, INC Ransom, Play, DragonForce, Sinobi) — HIGH · 2026-08-23
• ChocoPoC RAT Campaign Uses Malicious PoC-Exploit Python Packages to Backdoor Security Researchers — HIGH · 2026-07-02
• ChocoPoC Campaign: Trojanised PoC Exploits and PyPI Packages Deliver Python RAT Using Mapbox Datasets API as Dead-Drop C2 — HIGH · 2026-07-02
• ChocoPoC: Python RAT Distributed via Trojanized PoC Exploits Targeting Security Researchers — HIGH · 2026-07-01
• Palo Alto Networks PAN-OS / Prisma Access GlobalProtect Authentication Bypass (CVE-2026-0257) — Active Exploitation, CISA KEV — CRITICAL · 2026-05-29

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

• security.paloaltonetworks.com

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