Bug ID 1621977: Rewrite memoryleak with "REWRITE::disable" irule

Last Modified: Jan 29, 2026

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

Known Affected Versions:
16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1

Opened: Jul 31, 2024

Severity: 3-Major

Symptoms

Rewrite memory leak.

Impact

Rewrite memory usage is high.

Conditions

"REWRITE::disable" irule attached to virtual server.

Workaround

Avoid using 'REWRITE::disable' If only URL rewriting required (and not content rewriting), the below custom iRule which is designed exclusively for URL rewriting can be utilized, =========== when HTTP_REQUEST { if {[HTTP::host] equals "<JS file name>"} { HTTP::uri [string map {F5CH=J F5CH=I} [HTTP::uri]] HTTP::uri [string map {F5CH=H F5CH=I} [HTTP::uri]] } } ===========

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips