CVE-2026-40618: CWE-131 Incorrect Calculation of Buffer Size in F5 BIG-IP
When an SSL profile is configured on a virtual server on BIG-IP Virtual Edition (VE) without Intel QuickAssist Technology (QAT) or on BIG-IP hardware platforms with the database variable crypto.hwacceleration set to disabled, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AI Analysis
Technical Summary
This vulnerability arises from an incorrect buffer size calculation in the F5 BIG-IP Traffic Management Microkernel (TMM) when SSL profiles are used on virtual servers lacking Intel QuickAssist Technology or with hardware acceleration disabled. Under these conditions, certain traffic can trigger TMM termination, causing a denial of service. The issue affects multiple BIG-IP versions including 21.0.0, 17.5.0, 17.1.0, and 16.1.0. The CVSS 3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to availability. No vendor advisory or patch information is currently available, and no exploits have been observed in the wild.
Potential Impact
The vulnerability results in denial of service by causing the TMM process to terminate unexpectedly. There is no impact on confidentiality or integrity. The disruption affects availability of the BIG-IP service on affected versions when configured as described. No known active exploitation has been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider avoiding configurations that disable Intel QuickAssist Technology or hardware acceleration for SSL profiles on BIG-IP virtual servers. Monitor vendor communications for updates. No specific mitigation steps are provided by the vendor at this time.
CVE-2026-40618: CWE-131 Incorrect Calculation of Buffer Size in F5 BIG-IP
Description
When an SSL profile is configured on a virtual server on BIG-IP Virtual Edition (VE) without Intel QuickAssist Technology (QAT) or on BIG-IP hardware platforms with the database variable crypto.hwacceleration set to disabled, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability arises from an incorrect buffer size calculation in the F5 BIG-IP Traffic Management Microkernel (TMM) when SSL profiles are used on virtual servers lacking Intel QuickAssist Technology or with hardware acceleration disabled. Under these conditions, certain traffic can trigger TMM termination, causing a denial of service. The issue affects multiple BIG-IP versions including 21.0.0, 17.5.0, 17.1.0, and 16.1.0. The CVSS 3.1 base score is 7.5, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to availability. No vendor advisory or patch information is currently available, and no exploits have been observed in the wild.
Potential Impact
The vulnerability results in denial of service by causing the TMM process to terminate unexpectedly. There is no impact on confidentiality or integrity. The disruption affects availability of the BIG-IP service on affected versions when configured as described. No known active exploitation has been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider avoiding configurations that disable Intel QuickAssist Technology or hardware acceleration for SSL profiles on BIG-IP virtual servers. Monitor vendor communications for updates. No specific mitigation steps are provided by the vendor at this time.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- f5
- Date Reserved
- 2026-04-30T23:02:47.694Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a04970dcbff5d8610dff59a
Added to database: 5/13/2026, 3:21:49 PM
Last enriched: 5/13/2026, 4:06:24 PM
Last updated: 5/14/2026, 6:46:38 AM
Views: 2
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