SSL Profile Misconfig Causes TMM Crash on F5 BIG-IP VE/hardware
CVE-2026-40618 Published on May 13, 2026
BIG-IP SSL/TLS vulnerability
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.
Vulnerability Analysis
CVE-2026-40618 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Incorrect Calculation of Buffer Size
The software does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
Products Associated with CVE-2026-40618
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Affected Versions
F5 BIG-IP:- Version 21.1.0 and below * is unaffected.
- Version 21.0.0 and below 21.0.0.1 is affected.
- Version 17.5.0 and below 17.1.5.4 is affected.
- Version 17.1.0 and below 17.1.3.1 is affected.
- Version 16.1.0 and below * is affected.
- Version 2.0.0 and below * is affected.
- Version 1.7.0 and below * is affected.
- Version 2.0.0 and below * is affected.
- Version 1.1.0 and below * is affected.
- Version 2.0.0 and below 2.2.0 is affected.