Bug ID 561623: Realtime encryption causes high CPU usage in older browsers

Last Modified: Jul 18, 2026

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

Known Affected Versions:
11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3

Opened: Dec 06, 2015

Severity: 2-Critical

Symptoms

When encrypting using realtime encryption, CPU usage on the browser rises very high

Impact

In extreme cases, browser may prompt user to stop the encryption script.

Conditions

Client: Internet Explorer 8 or below FPS: Configured to encrypt password using realtime encryption

Workaround

Disable realtime encryption in your anti-fraud policy.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips