F5-K000156691: High severity F5 BIG-IP vulnerability

Published Oct 15, 2025
·
Updated

When the database variable tm.tcpudptxchecksum is configured as non-default value Software-only on a BIG-IP system, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate.

Affected Software

3 affected componentsFixes available
F5 BIG-IP>=17.5.0<=17.5.1, >=17.1.0<=17.1.2
17.5.1.317.1.3
F5 BIG-IP>=16.1.0<=16.1.6
16.1.6.1
F5 BIG-IP>=15.1.0<=15.1.10
15.1.10.8

Event History

Oct 15, 2025
Advisory Published
via F5·11:16 AM
Data Sourced
via F5·11:16 AM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of F5-K000156691?

F5-K000156691 is categorized as a high severity vulnerability due to its potential to cause the Traffic Management Microkernel (TMM) to terminate.

2

How do I fix F5-K000156691?

To fix F5-K000156691, configure the tm.tcpudptxchecksum database variable back to its default value.

3

Which versions of F5 BIG-IP are affected by F5-K000156691?

F5-K000156691 affects F5 BIG-IP versions 15.1.0 to 15.1.10, 16.1.0 to 16.1.6, and 17.1.0 to 17.5.1.

4

What is the cause of the F5-K000156691 vulnerability?

The vulnerability occurs when the tm.tcpudptxchecksum is set to a non-default value of Software-only, leading to TMM termination.

5

Is there a specific workaround for F5-K000156691?

The only recommended workaround for F5-K000156691 is to revert the tm.tcpudptxchecksum variable to its default configuration.

Contact

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