BugZero | F5 BugID 632400 - tmm may get stuck in a core loop during a failover...

F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

Last updated on July 18th, 2026

BugZero Risk Score
8.6 High

Overall: 8.6

Severity: 9.1

Community: 4.2

Lifecycle: 8.7

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Bug Details

Priority: 2-Critical
Status: Resolved
Impact Category: Local Traffic Manager

Description

Symptoms

During a failover event, it may be possible that the tmm cores on the newly active box causing another failover event where the next active box then cores again as well in a loop.

Impact

Production traffic is no longer serviced or is severely hindered.

Conditions

May occur during a failover event.

Workaround

Restarting both active and standby units should stop core loop.

Fix Information

None

Change history

Links

Original Vendor Announcement

Relevant Products

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Affected versions:11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 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, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6

Fixed versions: 13.1.0, 12.1.3.7, 11.6.3.2

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 13.1.0, 12.1.3.7, 11.6.3.2

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F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

Last updated on July 18th, 2026

BugZero Risk Score8.6 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

F5 - Defect ID: 632400

tmm may get stuck in a core loop during a failover event

Last updated on July 18th, 2026

BugZero Risk Score8.6 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
8.6 High

BugZero Risk Score
8.6 High