CVE-2026-40618
F5 Big-Ip Access Policy Manager 17.1.0 – 17.1.3
Raw vector
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:XSummary
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 Exploitation for Privilege Escalation (T1068); ranked at the 25th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-29976
Vulnerability Data
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…
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Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer security testing and code review can discover incorrect buffer-size computations before deployment.
Secure engineering principles directly require correct buffer-size arithmetic and bounds-checked allocation.
Input validation can enforce that supplied lengths or counts used in size calculations are within safe bounds.
Memory-protection mechanisms limit the exploitability of an overflow that results from an incorrect size calculation.
Flaw-remediation processes that include vulnerability scanning or static analysis will surface buffer-size errors.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent buffer-size miscalculations via coding standards, reviews, and testing, while fixing this single weakness only partially fulfills the broader control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding standards directly require correct buffer-size calculations.
Security testing can detect buffer-size errors before release.
Secure development lifecycle mandates size-checking practices that reduce buffer-size miscalculations.
Application security requirements can specify buffer-size validation rules.
Secure architecture principles include safe memory-allocation guidelines.