BugZero | F5 BugID 480982 - pkcs11d with a high thread count can result in hig...

F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

Last updated on July 18th, 2026

BugZero Risk Score
6.7 Medium

Overall: 6.7

Severity: 7.3

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: Local Traffic Manager

Description

Symptoms

When pkcs11d is set to use a very high thread count, CPU utilization can increase dramatically.

Impact

Less CPU available for other processes.

Conditions

The thread count for pkcs11d is set higher than the default.

Workaround

Do not set the db variable for pkcs11d thread count (/sys crypto fips external-hsm num-threads) higher than the default.

Fix Information

pkcs11d CPU utilization is far lower even with a high thread count.

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, 11.5.3, 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, 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

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 12.0.0

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F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

F5 - Defect ID: 480982

pkcs11d with a high thread count can result in high CPU utilization

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.7 Medium

BugZero Risk Score
6.7 Medium