Cyber Resilience

CVE-2026-42409

HighUpdated

Published: 13 May 2026

Published
13 May 2026
Modified
23 June 2026
KEV Added
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Patch
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CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0026 17.7th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-42409 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in F5 Big-Ip Access Policy Manager. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 17.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability details

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…

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Support (EoTS) are not evaluated.

CWE(s)
CWE-476

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Vulnerability in public-facing HTTP/2 virtual server allows crafted requests to trigger NULL dereference crash in TMM (DoS via application exploitation).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-20045Same product: F5 Big-Ip Access Policy Manager
CVE-2026-41956Same product: F5 Big-Ip Access Policy Manager
CVE-2025-21091Same product: F5 Big-Ip Access Policy Manager
CVE-2025-20058Same product: F5 Big-Ip Access Policy Manager
CVE-2025-21087Same product: F5 Big-Ip Access Policy Manager
CVE-2026-41218Same product: F5 Big-Ip Access Policy Manager
CVE-2026-41957Same product: F5 Big-Ip Access Policy Manager
CVE-2026-41225Same product: F5 Big-Ip Access Policy Manager
CVE-2025-24320Same product: F5 Big-Ip Access Policy Manager
CVE-2025-20029Same product: F5 Big-Ip Access Policy Manager

Affected Assets

f5
big-ip next cloud-native network functions
1.1.0 — 1.4.0 · 2.0.0 — 2.0.2
f5
big-ip next for kubernetes
2.0.0 — 2.1.0
f5
big-ip access policy manager
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip advanced firewall manager
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip advanced web application firewall
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip analytics
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip application acceleration manager
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip application security manager
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip application visibility and reporting
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
f5
big-ip automation toolchain
21.0.0 · 16.1.0 — 16.1.6 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1
+13 more product configuration(s) — see NVD for full list

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References