Palo Alto Networks PAN-OS Authentication Bypass
CVE-2026-0257 is a critical-severity reliance on cookies without validation and integrity checking vulnerability in Cloud NGFW from Palo Alto Networks, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on May 29, 2026, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update PAN-OS to 12.1.7, 12.1.4-h6 or 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17 or 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34, whichever matches your release line, or a later version.
- Update Prisma Access to 10.2.10-h36 or 11.2.7-h13, whichever matches your release line, or a later version.
- CISA's 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.
- Read the advisory on security.paloaltonetworks.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Palo Alto Networks | Cloud NGFW | Not specified in the record | Not stated |
| Palo Alto Networks | PAN-OS | 12.1.0 up to, but not including, 12.1.7, 12.1.4-h6; 11.2.0 up to, but not including, 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17; 11.1.0; 10.2.0 up to, but not including, 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34 | 12.1.7, 12.1.4-h6, 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17, 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 up to, but not including, 10.2.10-h36; 11.2.0 up to, but not including, 11.2.7-h13 | 10.2.10-h36, 11.2.7-h13 |
| Siemens | RUGGEDCOM APE1808 | all versions | Not stated |
| Siemens | Ruggedcom Ape1808 Firmware | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.8 | High | CNA (paloaltonetworks.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: 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.
How developers prevent this class of flaw
- Avoid using cookie data for a security-related decision.
- Perform thorough input validation (i.e.: server side validation) on the cookie data if you're going to use it for a security related decision.
- Add integrity checks to detect tampering.
More Reliance on Cookies without Validation and Integrity Checking vulnerabilities (CWE-565)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cert-portal.siemens.com/productcert/html/ssa-967325.htmlThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-0257US Government Resource
Other vulnerabilities in Cloud NGFW
- 7.2 High severity
Palo Alto Networks PAN-OS Code Injection Exploited
- 7.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.2 High severity
- 9.9 Critical severity
Recent Reliance on Cookies without Validation and Integrity Checking vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 9.8 Critical severity
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