Cyber Resilience

CVE-2026-40618

HighUpdated

Published: 13 May 2026

Published
13 May 2026
Modified
29 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:L/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 0.0032 24.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-40618 is a high-severity Incorrect Calculation of Buffer Size (CWE-131) 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 Application or System Exploitation (T1499.004); ranked at the 24.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

When an SSL profile is configured on a virtual server on BIG-IP Virtual Edition (VE) without Intel QuickAssist Technology (QAT) or on BIG-IP hardware platforms with the database variable crypto.hwacceleration set to disabled, undisclosed traffic can cause the Traffic Management…

more

Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CWE(s)
CWE-131

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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?

CVE enables crafted traffic to crash TMM via buffer calculation flaw (CWE-131), directly mapping to application exploitation for endpoint DoS.

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

CVEs Like This One

CVE-2026-20049Shared CWE-131
CVE-2019-25555Shared CWE-131
CVE-2026-29645Shared CWE-131
CVE-2024-11425Shared CWE-131
CVE-2024-8361Shared CWE-131
CVE-2025-1861Shared CWE-131
CVE-2026-20911Shared CWE-131
CVE-2026-1949Shared CWE-131
CVE-2025-66216Shared CWE-131
CVE-2026-1188Shared CWE-131

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
+14 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