BugZero | F5 BugID 466761 - Heartbeat, UDP packet with only double CRLF, on ex...

F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

Last updated on July 18th, 2026

BugZero Risk Score
6.9 Medium

Overall: 6.9

Severity: 7.3

Community: 4.2

Lifecycle: 8.3

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: Service Provider

Description

Symptoms

Heartbeat, UDP packet with only double CRLF, on existing SIP flow might result in connection loss.

Impact

Connection might be terminated.

Conditions

SIP heartbeat message, a UDP packet with double CRLF, sent by the client to the server.

Workaround

None.

Fix Information

The heartbeat SIP message, which is a UDP packet with CRLF, is ignored and connection is maintained.

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

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, 11.6.0, 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, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3

Fixed versions: 12.0.0, 11.5.3

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 12.0.0, 11.5.3

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F5 Integration

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F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

Last updated on July 18th, 2026

BugZero Risk Score6.9 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

F5 - Defect ID: 466761

Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

Last updated on July 18th, 2026

BugZero Risk Score6.9 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.9 Medium

BugZero Risk Score
6.9 Medium