CVE-2026-42409: CWE-476 NULL Pointer Dereference in F5 BIG-IP
When an HTTP/2 profile and an iRule containing the HTTP::redirect or HTTP::respond command are configured on a virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
AI Analysis
Technical Summary
CVE-2026-42409 is a NULL pointer dereference vulnerability (CWE-476) in the F5 BIG-IP Traffic Management Microkernel (TMM). It occurs when an HTTP/2 profile and an iRule containing HTTP::redirect or HTTP::respond commands are configured on a virtual server. Under certain undisclosed request conditions, this causes the TMM process to terminate, leading to denial of service. The vulnerability affects multiple BIG-IP versions (21.0.0, 17.5.0, 17.1.0, 16.1.0). No patch or official remediation level has been published by the vendor as of the data provided. The CVSS score of 7.5 indicates high severity due to ease of exploitation over the network without authentication or user interaction.
Potential Impact
The primary impact is denial of service caused by the termination of the TMM process, which can disrupt traffic management on affected BIG-IP virtual servers. There is no impact on confidentiality or integrity. The vulnerability can be triggered remotely over the network without authentication or user interaction, increasing the risk of service disruption.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider avoiding configurations that combine HTTP/2 profiles with iRules using HTTP::redirect or HTTP::respond commands on virtual servers. Monitor vendor communications for updates on patches or mitigations.
CVE-2026-42409: CWE-476 NULL Pointer Dereference in F5 BIG-IP
Description
When an HTTP/2 profile and an iRule containing the HTTP::redirect or HTTP::respond command are configured on a virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) process 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
CVE-2026-42409 is a NULL pointer dereference vulnerability (CWE-476) in the F5 BIG-IP Traffic Management Microkernel (TMM). It occurs when an HTTP/2 profile and an iRule containing HTTP::redirect or HTTP::respond commands are configured on a virtual server. Under certain undisclosed request conditions, this causes the TMM process to terminate, leading to denial of service. The vulnerability affects multiple BIG-IP versions (21.0.0, 17.5.0, 17.1.0, 16.1.0). No patch or official remediation level has been published by the vendor as of the data provided. The CVSS score of 7.5 indicates high severity due to ease of exploitation over the network without authentication or user interaction.
Potential Impact
The primary impact is denial of service caused by the termination of the TMM process, which can disrupt traffic management on affected BIG-IP virtual servers. There is no impact on confidentiality or integrity. The vulnerability can be triggered remotely over the network without authentication or user interaction, increasing the risk of service disruption.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider avoiding configurations that combine HTTP/2 profiles with iRules using HTTP::redirect or HTTP::respond commands on virtual servers. Monitor vendor communications for updates on patches or mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- f5
- Date Reserved
- 2026-04-30T23:04:10.873Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a049713cbff5d8610dffdf2
Added to database: 5/13/2026, 3:21:55 PM
Last enriched: 5/13/2026, 3:51:20 PM
Last updated: 5/14/2026, 6:46:37 AM
Views: 3
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