Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-20430 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Openwrt Openwrt. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th 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-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-20430 is an out-of-bounds write vulnerability stemming from an incorrect bounds check in WLAN Access Point (AP) firmware developed by MediaTek. This flaw, tracked under CWE-787, affects the firmware component responsible for handling wireless network operations. It was publicly disclosed on March 2, 2026, and carries a CVSS v3.1 base score of 8.8, reflecting its high severity due to the potential for significant impact on confidentiality, integrity, and availability.
Attackers positioned in the adjacent network segment, such as within proximal physical range (e.g., Wi-Fi proximity), can exploit this vulnerability remotely without requiring authentication privileges or user interaction. Successful exploitation enables escalation of privilege on the affected device, potentially allowing arbitrary code execution or system compromise with no additional execution privileges needed.
MediaTek's March 2026 Product Security Bulletin provides details on mitigation, including Patch ID WCNCR00467553 for addressing Issue ID MSV-5151. Security practitioners should apply this patch to vulnerable WLAN AP firmware deployments and monitor for updates via the referenced advisory at https://corp.mediatek.com/product-security-bulletin/March-2026.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9158
Vulnerability Data
In wlan AP FW, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.…
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Patch ID: WCNCR00467553; Issue ID: MSV-5151.
- 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 testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.
Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.
Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.
Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.
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-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
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.
Security testing in development and acceptance can detect and prevent out-of-bounds write defects.
Secure development life cycle mandates practices that prevent out-of-bounds writes.
Application security requirements can specify bounds-checking and safe memory handling.
Secure architecture and engineering principles reduce the likelihood of buffer overflows.
Secure coding directly addresses out-of-bounds writes through language choice and coding standards.
Change management can enforce review gates that catch unsafe memory operations before deployment.