Security readout for executives and security teams
Plain-English summary
CVE-2026-20419 is a MediaTek WLAN firmware issue that can make affected devices become unresponsive. An attacker must be nearby on the wireless network range; no user interaction or credentials are required. The business impact is availability disruption, not data theft or code execution based on current sources.
Executive priority
Treat as a moderate availability risk. Prioritize environments where wireless uptime matters, such as branch offices, retail, industrial, healthcare, and public access networks. The urgency is lower than remote code execution, but nearby unauthenticated disruption can still affect operations.
Technical view
The issue is an uncaught exception in MediaTek wlan AP/STA firmware, classified as CWE-754. CVSS 3.1 is 6.5 with adjacent-network access, low complexity, no privileges, no user interaction, and high availability impact. Listed patch IDs are WCNCR00461663 and WCNCR00463309; issue ID is MSV-4852.
Likely exposure
Exposure depends on whether products use the listed MediaTek chipsets and firmware branches. Affected chipsets include MT6890, MT7902, MT7915, MT7916, MT7921, MT7922, MT7925, MT7981, MT7986, MT8196, and others named in the CVE record.
Exploitation context
Sources describe remote proximal or adjacent denial of service. There is no KEV listing and no provided source states active exploitation. Exploitation would require wireless proximity, reducing internet-scale risk but increasing concern for offices, public venues, and unmanaged wireless environments.
Researcher notes
The public record does not provide protocol details, trigger conditions, affected firmware versions, or exploit indicators. Avoid assuming all devices with these chipsets are exposed; OEM firmware integration determines practical impact. Validate through vendor firmware advisories and patch ID mapping.
Mitigation direction
- Check MediaTek’s February 2026 bulletin and OEM advisories for firmware containing the listed patch IDs.
- Prioritize updates for Wi-Fi infrastructure, gateways, embedded devices, and high-availability endpoints using affected chipsets.
- If updates are unavailable, ask the device vendor for exposure confirmation and remediation timing.
- Monitor wireless availability incidents near sensitive sites until patched.
Validation and detection
- Inventory devices and modules using the affected MediaTek chipset list.
- Confirm firmware versions and patch status with the OEM or MediaTek advisory.
- Track whether patch IDs WCNCR00461663 or WCNCR00463309 are included in vendor firmware.
- Review WLAN crash or reset logs for unexplained availability events.
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-754: 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-2026-20419 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.
Improper Check for Unusual or Exceptional Conditions
Improper Check for Unusual or Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.