BugZero | F5 BugID 713066 - Connection failure during DNS lookup to disabled n...

F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

Last updated on July 18th, 2026

BugZero Risk Score
8.4 High

Overall: 8.4

Severity: 9.1

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 2-Critical
Status: Verified
Impact Category: Global Traffic Manager (DNS)

Description

Symptoms

TMM restart as a result of a DNS lookup to disabled nameserver.

Impact

TMM restarts. Traffic disrupted while tmm restarts.

Conditions

DNS lookup that tries to connect to a nameserver that is not reachable for some reason. This could be an explicit 'RESOLV::lookup' command in iRule, or it could be DNS lookups internally triggered by APM or HTTP.

Workaround

Verify connectivity to nameserver. As an alternative, refrain from using RESOLV::lookup in iRules.

Fix Information

This issue is now fixed.

Change history

Links

Original Vendor Announcement

Relevant Products

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Affected versions: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, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7

Fixed versions: 14.1.0, 14.0.0, 13.1.0.8, 12.1.3.6

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 14.1.0, 14.0.0, 13.1.0.8, 12.1.3.6

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F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

Last updated on July 18th, 2026

BugZero Risk Score8.4 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

F5 - Defect ID: 713066

Connection failure during DNS lookup to disabled nameserver can crash TMM

Last updated on July 18th, 2026

BugZero Risk Score8.4 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
8.4 High

BugZero Risk Score
8.4 High