PAN-OS Authentication Bypass Enabling Unauthorized VPN Tunnels Affects Palo Alto Networks Prisma Access and Siemens RUGGEDCOM APE1808; Now Listed in CISA's Known Exploited Vulnerabilities Catalog

Last refreshed2026-09-27

Status: KEV | Advisory ID: CVE-2026-0257

Key Details

CVE	CVE-2026-0257
Vulnerability Name	Palo Alto Networks PAN-OS Authentication Bypass Vulnerability
Affected products	Siemens RUGGEDCOM APE1808 Firmware, Palo Alto Networks Prisma Access, and Palo Alto Networks PAN-OS
Exploitation status	Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified as	CWE-565 (Reliance on Cookies without Validation and Integrity Checking)
KEV listing	Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-05-29.
Exploitation prediction (EPSS)	96.38% probability of exploitation in the next 30 days (100% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline	2026-06-01 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
Siemens	RUGGEDCOM APE1808 Firmware
Palo Alto Networks	Prisma Access
Palo Alto Networks	PAN-OS

Vendor

Product

Affected Versions

Patch Status

Siemens

RUGGEDCOM APE1808 Firmware

Palo Alto Networks

Prisma Access

Palo Alto Networks

PAN-OS

Subsystems	PLC/PAC/RTU
Sectors	Critical Manufacturing, Energy, Food and Agriculture, Multi-sector, Transportation Systems

What to Know

Palo Alto Networks PAN-OS contains an authentication bypass vulnerability that allows attackers to bypass security restrictions and establish an unauthorized VPN connection.

What to Do

Monitor Siemens's and Palo Alto Networks's web pages for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-0257
CVE	https://www.cve.org/CVERecord?id=CVE-2026-0257

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-0257

CVE

https://www.cve.org/CVERecord?id=CVE-2026-0257

KEV Required Action

Field	Value
KEV Link	https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV	2026-05-29
Required Action Due Date	2026-06-01
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.

Field

Value

KEV Link

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Date Added to KEV

2026-05-29

Required Action Due Date

2026-06-01

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.