Disclaimer

Known affected versions were inferred from fixed-version data and were not explicitly confirmed by the vendor: 8.1.13, 9.1.2

The earliest recollection of this bug is traced back to PAN-OS 8.1.14 - July 22, 2025. This bug is fixed in PAN-OS versions 9.1.3, 8.1.14. Fixed an issue where after upgrading the passive firewall, the outer UDP sessions synced from the active firewall did not retain the rule information and after failover, GPRS tunneling protocol (GTP) inspection did not work. Fixed an issue in a high availability (HA) configuration where, after upgrading the passive firewall, the outer UDP sessions synced from the active firewall did not retain rule information and GPRS tunneling protocol (GTP) inspection failed after failover. For more information: https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-14-addressed-issues https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-3-addressed-issues