---
title: "CVE-2026-0257: Palo Alto Networks PAN-OS Authentication Bypass Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-0257/
description: "CVE-2026-0257 (Palo Alto Networks PAN-OS): Exploited in the wild (CISA KEV). Authentication bypass vulnerabilities in the GlobalProtect portal and gateway…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-13
date_modified: 2026-10-15
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-0257"
kev: true
cvss: 7.8
epss: 0.96895
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Palo Alto Networks PAN-OS. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-05-29, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-06-01 ; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns .
- EPSS 96.9% , percentile 99.9: FIRST’s model estimates a 96.9% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

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.

## Affected products (CVE record)

- Palo Alto Networks Cloud NGFW: see advisory
- Palo Alto Networks PAN-OS: 12.1.0 < 12.1.7, 12.1.4-h6, 11.2.0 < 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17, 11.1.0 < 11.1.15, 11.1.13-h5, 11.1.10-h25, 11.1.7-h6, 11.1.6-h32, 11.1.4-h33, 10.2.0 < 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34
- Palo Alto Networks Prisma Access: 10.2.0 < 10.2.10-h36, 11.2.0 < 11.2.7-h13

## Severity

- palo_alto CVSS 4.0: 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`

## Exploitation

- CISA KEV: added 2026-05-29; federal due date 2026-06-01. Known ransomware use: Known.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 96.89% probability of exploitation activity in the next 30 days; percentile 99.9.

## Sources

- [security.paloaltonetworks.com](https://security.paloaltonetworks.com/CVE-2026-0257)
- [CVE.org record CVE-2026-0257](https://www.cve.org/CVERecord?id=CVE-2026-0257)
- [NVD entry CVE-2026-0257](https://nvd.nist.gov/vuln/detail/CVE-2026-0257)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-0257)
- [cert-portal.siemens.com](https://cert-portal.siemens.com/productcert/html/ssa-967325.html)

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Source page: https://erroneo.us/security/cve/CVE-2026-0257/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt