Security readout for executives and security teams
Plain-English summary
CVE-2026-20406 is a MediaTek modem vulnerability that can crash an affected device when it connects to an attacker-controlled rogue base station. It is a denial-of-service issue, not a data theft or code execution issue based on available sources. The business risk is localized service disruption for devices using listed MediaTek chipsets.
Executive priority
Treat this as a moderate availability risk for mobile, IoT, automotive, or embedded fleets using affected MediaTek chipsets. Prioritize inventory and OEM firmware confirmation. Escalate faster where device connectivity is mission-critical or field devices operate in untrusted radio environments.
Technical view
The issue is an uncaught exception in the MediaTek modem component, classified as CWE-770. CVSS 3.1 is 6.5 with adjacent attack vector, low complexity, no privileges, no user interaction, and high availability impact. MediaTek identifies Patch ID MOLY01726634 and Issue ID MSV-5728.
Likely exposure
Exposure applies to devices containing the listed MediaTek chipsets, including MT27xx, MT68xx, MT69xx, MT86xx, MT87xx, and MT88xx series entries in the CVE record. Practical exposure requires a UE connecting to a rogue base station controlled by an attacker.
Exploitation context
Sources describe remote denial of service through a rogue base station, with no user interaction or privileges required. The CVE is not listed as KEV in the provided bundle, and no cited source states active exploitation. Attack feasibility depends on radio proximity and rogue base-station capability.
Researcher notes
Available public detail is limited to the CVE description and MediaTek bulletin reference. Do not assume exploit availability, broader impact, or specific device models beyond the chipset list. Validation should focus on asset-to-chipset mapping and vendor firmware status, not live rogue base-station testing.
Mitigation direction
- Review MediaTek February 2026 bulletin for Patch ID MOLY01726634 guidance.
- Ask device OEMs or carriers for firmware availability for affected chipsets.
- Prioritize managed fleets using listed MediaTek modem chipsets.
- Apply vendor-approved modem or device firmware updates when available.
- If no update is available, follow OEM risk-reduction guidance.
Validation and detection
- Inventory devices and map models to MediaTek chipset identifiers.
- Check OEM firmware release notes for CVE-2026-20406 or MOLY01726634.
- Confirm installed baseband or modem firmware versions against vendor guidance.
- Track unsupported devices that cannot receive modem firmware updates.
- Monitor vendor advisories for revised affected-product or remediation details.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-770: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-20406 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://corp.mediatek.com/product-security-bulletin/February-2026CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.