Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-20433 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Mediatek Mt2735 Firmware. 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 27th 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-2026-20433 is an out-of-bounds write vulnerability (CWE-787) in the Modem component, stemming from a missing bounds check. It affects MediaTek modem implementations, as detailed in the vendor's security bulletin. Published on April 7, 2026, the issue carries a CVSS v3.1 base score of 8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and is tracked under Patch ID MOLY01088681 and Issue ID MSV-4460.
The vulnerability can be exploited remotely for escalation of privilege when a user equipment (UE) connects to a rogue base station controlled by an attacker. No additional execution privileges are required on the attacker's part, though user interaction is needed for the UE to connect. Successful exploitation could grant high confidentiality, integrity, and availability impacts in an adjacent network setting with low attack complexity.
MediaTek's April 2026 product security bulletin at https://corp.mediatek.com/product-security-bulletin/April-2026 provides details on the issue, including the associated patch MOLY01088681 for mitigation.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19568
Vulnerability Data
In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, if a UE has connected to a rogue base station controlled by the attacker, with no…
more
additional execution privileges needed. User interaction is needed for exploitation. Patch ID: MOLY01088681; Issue ID: MSV-4460.
- 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.