Bug ID 2183233: TMM crash due to extra trailing CR/LF in iSession reconnects

Last Modified: Jan 27, 2026

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

Known Affected Versions:
17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3

Opened: Dec 09, 2025

Severity: 3-Major

Symptoms

On BIG-IP APM systems, a Traffic Management Microkernel (TMM) crash may occur when a client device sends an extra trailing carriage return/line feed (CR/LF) during an iSession tunnel reconnect. This issue was observed to be triggered by a specific client device and user scenario, where the Edge Client installation was a hybrid of multiple versions, resulting in the transmission of unexpected CR/LF characters after the iSession request.

Impact

Traffic disrupted while tmm restarts. Disruption of user sessions. The issue is highly specific to certain client configurations and is not expected to be widespread.

Conditions

iSession tunnels in use. Client device sends an extra CR/LF after the iSession request, often due to a hybrid or corrupted Edge Client installation.

Workaround

None.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips