High [CVE-2026-39458] When a BIG-IP is configured with DNS caching (Such as a DNS profile with caching enabled, SSL Orchestrator, Advanced WAF DoS protection), undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate
This high-severity F5 advisory covers CVE-2026-39458 affecting BIG-IP.
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Summary
When a BIG-IP is configured with DNS caching (Such as a DNS profile with caching enabled, SSL Orchestrator, Advanced WAF DoS protection), 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.
- BIG-IP 21.0.0 before 21.0.0.1
- BIG-IP 17.5.0 before 17.5.1.6
- BIG-IP 17.1.0 before 17.1.3.2
- BIG-IP 16.1.0
Official advisory · high-confidence parse· fetched 18 hours ago·verify at source
- 21.0.0.1
- 17.5.1.6
- 17.1.3.2
Official advisory · high-confidence parse· fetched 18 hours ago·verify at source
Mitigation
Upgrade to a fixed release: 21.0.0.1, 17.5.1.6, 17.1.3.2. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 18 hours ago·verify at source
Discussion(0)
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