How to Fix CVE-2026-0257: Critical Vulnerability in Cloud NGFW

Related fixes

Other vulnerabilities in the same area that are worth patching alongside this one:

• How to Fix CVE-2026-0263: Command Injection in Cloud NGFW — Command Injection in Cloud NGFW
• How to Fix CVE-2026-2914: Privilege escalation in Endpoint Privilege Manager Agent — Privilege escalation in Endpoint Privilege Manager Agent
• How to Fix CVE-2026-0300: Out-of-Bounds Write in Cloud NGFW , Out-of-Bounds Write in Cloud NGFW
• How to Fix CVE-2026-0229: Denial of Service in Cloud NGFW , Denial of Service in Cloud NGFW
• How to Fix CVE-2026-0248: Authentication Bypass in Prisma Access Agent , Authentication Bypass in Prisma Access Agent

*By Sai Kiran Pandrala*

What is CVE-2026-0257?

CVE-2026-0257 is a security flaw in Cloud NGFW. 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.

Why this CVE matters

Unpatched network-facing software is the leading initial-access vector in public breach reporting. Treat any CVSS-9 class flaw on an internet-reachable system as urgent, regardless of whether public exploit code has been observed yet.

For deployments of Cloud NGFW that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

• Cloud NGFW: 12.1.0 < 12.1.7, 12.1.4-h6
• Cloud NGFW: 11.2.0 < 11.2.12, 11.2.10-h7, 11.2.7-h14, 11.2.4-h17
• Cloud NGFW: 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
• Cloud NGFW: 10.2.0 < 10.2.18-h6, 10.2.16-h7, 10.2.13-h21, 10.2.10-h36, 10.2.7-h34
• Cloud NGFW: 10.2.0 < 10.2.10-h36
• Cloud NGFW: 11.2.0 < 11.2.7-h13

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

On PAN-OS, run show system info | match sw-version from the CLI, or read the Dashboard widget in the GUI.

How to fix CVE-2026-0257

1. Read the vendor advisory in full: https://security.paloaltonetworks.com/CVE-2026-0257
2. Upgrade Cloud NGFW to All or a later version listed in the vendor advisory.
3. Back up the configuration (and database, where applicable) before upgrading.
4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Upgrade PAN-OS to the patched release

# Target PAN-OS build All.
show system info | match sw-version

request system software download version All
request system software install version All
request restart system

# Post-reboot verification
show system info | match sw-version

Verify the fix landed

# 1. Confirm the running version matches the fixed-in version from the advisory:
#    https://security.paloaltonetworks.com/CVE-2026-0257
#    Use the platform-specific version probe above.

# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag CVE-2026-0257 on the patched target.

# 3. Inspect recent service / kernel logs for crash loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

If you cannot patch immediately

Restrict access to the management interface to trusted internal IP addresses only. Block public access at the firewall and require VPN for any remote administration. Apply the patch as soon as a maintenance window allows.

How to verify the fix worked

• After applying the patch, verify the running version in the product's admin UI or via the vendor-documented CLI command.
• Confirm the patched build matches the version listed in the vendor advisory.
• Run an authenticated vulnerability scan with a current signature set and confirm the scanner no longer flags CVE-2026-0257.
• Review logs for the entire pre-patch window for indicators of compromise listed in the vendor or CISA advisory.
• Confirm any network-layer mitigations that were applied as a stopgap have been reverted (or left in place intentionally) once the patch is verified.

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for log entries that do not match your normal request patterns, especially repeated requests to the same uncommon endpoint, and any administrative changes you cannot tie back to a known operator.

Frequently asked questions

Is CVE-2026-0257 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-0257?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for Cloud NGFW run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

• Official vendor advisory: https://security.paloaltonetworks.com/CVE-2026-0257
• NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-0257
• CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*