F5 Products Denial of Service Vulnerability

A vulnerability was identified in F5 Products. A remote attacker could exploit this vulnerability to trigger denial of service condition on the targeted system.

 

Note:

No patch is currently available for CVE-2026-42534 of the affected products. Hence, the risk level is rated as High Risk.

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Impact

• Denial of Service

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System / Technologies affected

BIG-IP Next SPK

 

• 2.0.0 - 2.0.3
• 1.7.0 - 1.9.2

 

BIG-IP Next CNF

 

• 2.0.0 - 2.3.2
• 1.1.0 - 1.4.3

 

BIG-IP Next for Kubernetes

 

• 2.0.0 - 2.3.2

 

BIG-IP DNS

 

• 21.1.03
• 17.5.0 - 17.5.13
• 17.1.0 - 17.1.33

 

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Solutions

Notes: No patch is currently available.

 

Workaround:

Mitigate the vulnerability of attacks by following workaround:

 

• Restrict upstream DNS servers. Ensure that the DNS cache resolvers on your BIG-IP systems are configured to query only trusted, internal DNS servers.
• Use DNS over Transport Layer Security (TLS). If supported, configure DNS resolution over TLS to prevent man-in-the-middle (MITM) attacks on the DNS path that could inject crafted Extension Mechanisms for DNS (EDNS) responses.
• Network segmentation: Isolate the DNS resolution path so that upstream DNS servers are on a trusted, protected network segment.
• Limit DNS features: If provisioning DNS or DNS cache resolution are not required, disable them to eliminate the attack surface entirely.

 

Please visit the vendor web-site for more details.

 

Apply workarounds issued by the vendor:

• https://my.f5.com/manage/s/article/K000162784

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Vulnerability Identifier

• CVE-2026-42534

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Source

• F5

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Related Link

https://my.f5.com/manage/s/article/K000162784