High severity · published May 13, 2026
CVE-2026-42409
BIG-IP HTTP/2 vulnerability
7.5
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BI
BIG-IP · F5
21.0.0 before 21.0.0.1; 17.5.0 before 17.5.1.4; 17.1.0 before 17.1.3.1; 16.1.0 · source: vendor
BN
BIG-IP Next CNF · F5
2.0.0 before 2.0.3; 1.4.0 before 1.4.1 · source: vendor
BN
BIG-IP Next SPK · F5
2.0.0 before 2.0.3; 1.7.0 before 1.7.17 · source: vendor
BN
BIG-IP Next for Kubernetes · F5
2.0.0 before 2.1.1 · source: vendor, NVD
BA
Big-ip Access Policy Manager · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Advanced Firewall Manager · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Advanced Web Application Firewall · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Analytics · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Application Acceleration Manager · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Application Security Manager · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Application Visibility And Reporting · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
BA
Big-ip Automation Toolchain · F5
21.0.0; 16.1.0 through 16.1.6; 17.1.0 through 17.1.3; 17.5.0 through 17.5.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42409
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42409
Mitigation
https://my.f5.com/manage/s/article/K000159034
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