Security readout for executives and security teams
Plain-English summary
A flaw in Microsoft 365 Copilot could let an unauthenticated network attacker expose sensitive information after user interaction. The issue affects confidentiality, with no documented integrity or availability impact. Exact affected versions are not specified in the supplied sources.
Executive priority
Treat this as a moderate, near-term remediation item. Prioritize environments where Copilot can access sensitive business information, while recognizing that user interaction is required and active exploitation is not established.
Technical view
CVE-2026-42827 is a CWE-77 command-injection weakness caused by improper neutralization of command elements. It has CVSS 3.1 score 6.5: network-accessible, low complexity, no privileges required, and user interaction required, with high confidentiality impact only.
Likely exposure
Organizations using Microsoft 365 Copilot may be exposed. The supplied record provides no affected version range or CPE identifiers, so applicability must be confirmed through Microsoft’s advisory and tenant deployment status.
Exploitation context
The CVE is not listed as KEV in the supplied bundle. Its CVSS temporal metric reports exploit maturity as unproven. No supplied evidence establishes active exploitation or a publicly available exploit.
Researcher notes
The record identifies command injection and information disclosure but omits affected versions, attack mechanics, exposed data types, and detection indicators. Avoid assuming broader Microsoft 365 impact. Validation should remain defensive and follow Microsoft’s published guidance.
Mitigation direction
- Review Microsoft’s CVE advisory for current remediation and applicability details.
- Apply the Microsoft-provided update or remediation according to vendor guidance.
- Limit sensitive Copilot access where practical until remediation status is confirmed.
- Remind users to treat unexpected Copilot content or interaction requests cautiously.
Validation and detection
- Inventory tenants and users with Microsoft 365 Copilot enabled.
- Confirm affected-product applicability against Microsoft’s advisory.
- Verify the vendor-prescribed update or remediation is active.
- Review relevant audit telemetry for unusual Copilot-mediated information access or disclosure.
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-77: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-42827 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:N/AC:L/PR:N/UI:R/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:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C2.83.6microsoftVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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
- M365 Copilot 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.
Improper Neutralization of Special Elements used in a Command ('Command Injection')
Improper Neutralization of Special Elements used in a Command ('Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.