Bug ID 1027961: Changes to an admin user's account properties may result in MCPD crash and failover

Last Modified: Jun 15, 2024

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,,, 17.0.0,,

Opened: Jun 22, 2021

Severity: 2-Critical


-- The mcpd process fails with a segmentation fault and restarts, leaving a core-dump file. -- Active sessions in the Configuration Utility report "unable to contact BIG-IP device". -- Various processes may record entries into the "ltm" log saying "Lost connection to mcpd."


The failure and restart of mcpd will trigger a restart of many other processes, including the TMM daemons, thus interrupting network traffic handling. In high availability (HA) configurations, a failover will occur.


-- Changes to properties of administrative user-login accounts are occurring. -- A user account being changed has a current, active session in the Configuration Utility GUI.


Before making changes to the account properties of an administrative user, where the changes affect the role, make certain that all GUI Configuration Utility sessions opened by that user are logged out.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips