Security readout for executives and security teams
Plain-English summary
A flaw in Windows Internet Connection Sharing can let an unauthorized person with physical access read information outside an intended memory boundary. The principal business risk is exposure of sensitive data; the supplied evidence does not indicate data modification, service disruption, or remote exploitation.
Executive priority
Schedule remediation through the normal security-update cycle, accelerating systems with sensitive data or weak physical controls. This is not presented as an internet-scale emergency, but the potential confidentiality impact warrants verified patch coverage rather than relying solely on physical-security assumptions.
Technical view
CVE-2026-20828 is a CWE-125 out-of-bounds read involving Windows rndismp6.sys and Internet Connection Sharing. Its CVSS 3.1 score is 4.6: physical access, low complexity, no privileges, and no user interaction, with high confidentiality impact but no stated integrity or availability impact.
Likely exposure
Exposure concerns the listed Windows 10, Windows 11, and Windows Server versions. Risk is greatest where affected systems handle sensitive information and an untrusted person could obtain physical access. The bundle does not provide precise configuration prerequisites or complete patched-build boundaries.
Exploitation context
The CVE is not listed as KEV in the supplied bundle. No cited source here establishes active exploitation or public exploit availability. Exploitation requires physical access according to the description, materially limiting broad remote attack potential while remaining relevant for shared, unattended, or physically exposed systems.
Researcher notes
The supplied vector is AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N with exploit maturity unproven, an official fix available, and confirmed reporting confidence. The bundle identifies an out-of-bounds read but provides no root-cause detail, trigger conditions, disclosed data scope, patch identifiers, or evidence of exploitation.
Mitigation direction
- Review Microsoft’s CVE advisory and apply the security update appropriate for each affected Windows release.
- Prioritize physically accessible endpoints and servers that process sensitive information.
- Restrict untrusted physical access while updates are pending.
- Review whether Internet Connection Sharing is required and follow Microsoft guidance before changing its configuration.
Validation and detection
- Inventory systems running the Windows releases listed in the CVE bundle.
- Use Microsoft’s advisory to identify applicable updates and supported build requirements.
- Confirm the applicable security update is installed through approved endpoint-management records.
- Identify affected systems with untrusted physical-access scenarios and document compensating controls.
- Recheck Microsoft guidance for revised affected-version or remediation details.
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-125: 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-2026-20828 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
- 4.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
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.
SSVC decision data
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:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C0.93.6microsoftVulnerability scoring details
Base CVSS 3.1 score
4.6MediumVector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Windows rndismp6.sys Information Disclosure VulnerabilityCVE reference, microsoft · vendor-advisory, patch
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 Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.