Cyber Resilience

CVE-2026-39458

HighUpdated

Published: 13 May 2026

Published
13 May 2026
Modified
29 June 2026
KEV Added
—
Patch
—
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-2026-39458 is a high-severity Access of Uninitialized Pointer (CWE-824) 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 Endpoint Denial of Service (T1499); ranked at the 17.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

When a BIG-IP DNS profile enabled with DNS cache is configured on a virtual server, 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.

CWE(s)
CWE-824

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
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?

DoS via crafted traffic exploiting uninitialized pointer in TMM service directly maps to endpoint DoS by application exploitation.

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

CVEs Like This One

CVE-2025-2284Shared CWE-824
CVE-2026-2100Shared CWE-824
CVE-2026-42959Shared CWE-824
CVE-2026-21276Shared CWE-824
CVE-2026-2785Shared CWE-824
CVE-2026-2805Shared CWE-824
CVE-2026-44411Shared CWE-824
CVE-2025-26599Shared CWE-824
CVE-2026-28691Shared CWE-824
CVE-2024-57943Shared CWE-824

Affected Assets

f5
big-ip access policy manager
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip advanced firewall manager
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip advanced web application firewall
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip analytics
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip application acceleration manager
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip application security manager
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip application visibility and reporting
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip automation toolchain
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip carrier-grade nat
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
f5
big-ip container ingress services
21.0.0 · 17.1.0 — 17.1.3 · 17.5.0 — 17.5.1 · 16.1.0 — 16.1.6
+11 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