Bug ID 2139921: Invalid Length PCRE Expression Was Allowed Through REST API

Last Modified: Apr 22, 2026

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

Known Affected Versions:
15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.1.6, 16.1.6.1, 17.1.3, 17.1.3.1, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5

Opened: Oct 24, 2025

Severity: 2-Critical

Symptoms

The regex validation string for parameters is intended to be limited to a maximum length of 254 characters, but this validation was not enforced correctly via the REST API.

Impact

ASM goes into a restart loop.

Conditions

A lengthy PRCE expression is set for a parameter using the REST API

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips