Security readout for executives and security teams
Plain-English summary
CVE-2026-20417 is a MediaTek PCIe driver/chipset vulnerability that could let a local attacker increase privileges after they already have System-level access. It does not require user interaction. Business urgency is moderate: it matters most for devices using the listed MediaTek chipsets, but current sources do not show active exploitation.
Executive priority
Treat as a moderate-priority patching item for fleets with affected MediaTek-based devices. It is not currently supported as internet-exploitable or actively exploited, but it can deepen compromise on already-affected devices. Prioritize based on chipset presence, device criticality, and availability of OEM updates.
Technical view
The issue is an out-of-bounds write in pcie caused by a missing bounds check, mapped to CWE-787. MediaTek lists affected chipset versions MT6991, MT6993, and MT8678. CVSS v3.1 is 5.3 with local attack vector, low complexity, low privileges, no user interaction, and limited confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to products incorporating the affected MediaTek chipsets: MT6991, MT6993, and MT8678. Organizations are most likely exposed through phones, tablets, embedded, or OEM devices using those chipsets. The source bundle does not identify specific device models or operating system builds.
Exploitation context
Public sources describe local escalation of privilege after the attacker already has System privilege. No user interaction is required. The CVE is not listed as KEV in the provided data, and no cited source states active exploitation or public exploit availability.
Researcher notes
Evidence is limited to the CVE record and MediaTek bulletin reference. The affected scope is chipset-level, not device-model-specific. The description contains both CVSS PR:L and text requiring existing System privilege; validate privilege assumptions against vendor advisory details before risk scoring internally.
Mitigation direction
- Review MediaTek’s February 2026 bulletin for patch guidance and applicability.
- Prioritize firmware or OS updates from device OEMs that include ALPS10314946 or ALPS10340155.
- Inventory devices for MediaTek MT6991, MT6993, and MT8678 chipsets.
- If no OEM update is available, monitor vendor guidance and restrict high-privilege local access.
Validation and detection
- Confirm whether managed devices use MT6991, MT6993, or MT8678 chipsets.
- Check OEM security bulletin or firmware notes for ALPS10314946 or ALPS10340155.
- Verify deployed firmware or OS build date includes the MediaTek February 2026 fixes.
- Track CVE-2026-20417 in vulnerability management until vendor remediation is confirmed.
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-787: 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-2026-20417 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
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L1.83.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.